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xboard - X graphical user interface for chess

Authors And Contributors

       Chris Sears and Dan Sears wrote the original XBoard.  They were responsible for versions 1.0 through 1.2.
       The color scheme was taken from Wayne Christopher's `XChess' program.

       Tim  Mann  was  primarily  responsible for XBoard versions 1.3 through 4.2.7, and for WinBoard (a port of
       XBoard to Microsoft Win32) from its inception through version 4.2.7.

       John Chanak contributed the initial implementation of ICS mode.  Evan Welsh wrote  `CMail',  and  Patrick
       Surry  helped  in designing, testing, and documenting it.  Elmar Bartel contributed the new piece bitmaps
       introduced in version 3.2.  Jochen Wiedmann converted the  documentation  to  texinfo.   Frank  McIngvale
       added  click/click moving, the Analysis modes, piece flashing, ZIICS import, and ICS text colorization to
       XBoard.  Hugh Fisher added animated piece movement to XBoard, and Henrik Gram added it to WinBoard.  Mark
       Williams contributed the initial (WinBoard-only) implementation of many new features added to both XBoard
       and WinBoard in version 4.1.0, including copy/paste, premove, icsAlarm, autoFlipView, training mode, auto
       raise, and blindfold.  Ben Nye contributed X copy/paste code for XBoard.

       In a fork from version 4.2.7, Alessandro Scotti added many elements to the user  interface  of  WinBoard,
       including  the  board  textures  and font-based rendering, the evaluation-graph, move-history and engine-
       output window.  He was also responsible for adding the UCI support.

       H. G. Muller continued this fork of the project, producing version 4.3.  He made WinBoard  castling-  and
       e.p.-aware,  added  variant  support  with adjustable board sizes, the crazyhouse holdings, and the fairy
       pieces.  In addition he added most of the adjudication options, made WinBoard more robust in dealing with
       buggy and crashing engines, and extended time control with a time-odds and node-count-based modes.   Most
       of the options that initially were WinBoard only have now been back-ported to XBoard.

       Michel van den Bergh provided the code for reading Polyglot opening books.

       Meanwhile,  some  work  continued  on  the GNU XBoard project maintained at savannah.gnu.org, but version
       4.2.8 was never released.  Daniel Mehrmann was responsible for much of this work.

       Most recently, Arun Persaud worked with H. G. Muller to merge all  the  features  of  the  never-released
       XBoard/WinBoard  4.2.8  of  the GNU XBoard project and the never-released 4.3.16 from H. G.'s fork into a
       unified XBoard/WinBoard 4.4, which is now available both from  the  savannah.gnu.org  web  site  and  the
       WinBoard forum.

Basic Operation

       To  move a piece, you can drag it with the left mouse button, or you can click the left mouse button once
       on the piece, then once more on the destination square. To under-promote a Pawn you can drag it backwards
       until it morphs into the piece you want to promote to, after which you drag that forward to the promotion
       square.  Or after selecting the pawn with a first click you can then click the promotion square and  move
       the  mouse  while  keeping the button down until the piece that you want appears in the promotion square.
       To castle you move the King to its destination or, in Chess960, on top of the Rook  you  want  to  castle
       with.   In  crazyhouse,  bughouse  or  shogi  you can drag and drop pieces to the board from the holdings
       squares displayed next to the board.

       Old behavior, where right-clicking a square brings up a menu where you can select what piece to  drop  on
       it  can  still  be  selected through the `Drop Menu' option.  Only in Edit Position mode right and middle
       clicking a square is still used to put a piece on it, and the piece to drop is selected by  sweeping  the
       mouse vertically with the button held down.

       The  default  function  of  the  right  mouse  button in other modes is to display the position the chess
       program thinks it will end up in.  While moving the mouse vertically with this button pressed XBoard will
       step through the principal variation to show how this position will be reached.  Lines of play  displayed
       in  the  engine-output window, or PGN variations in the comment window can similarly be played out on the
       board, by right-clicking on them.  Only in Analysis mode, when you walk along a PV, releasing  the  mouse
       button might forward the game upto that point, like you entered all previous PV moves.  As the display of
       the  PV  in  that  case  starts  after  the first move a simple right-click will play the move the engine
       indicates.

       In Analysis mode you can also make a move by grabbing the piece with a double-click  of  the  left  mouse
       button  (or  while  keeping the `Ctrl' key pressed).  In this case the move you enter will not be played,
       but will be excluded from the analysis of the current position.  (Or included if it was already excluded;
       it is a toggle.)  This only works for engines that support this feature.

       When connected to an ICS, it is possible to call up a graphical representation of players seeking a  game
       in  stead of the chess board, when the latter is not in use (i.e. when you are not playing or observing).
       Left-clicking the display area will switch between this 'seek graph' and the chess board.   Hovering  the
       mouse  pointer  over  a  dot  will  show the details of the seek ad in the message field above the board.
       Left-clicking the dot will challenge that player.  Right-clicking a dot will 'push it to  the  back',  to
       reveal any dots that were hidden behind it.  Right-clicking off dots will refresh the graph.

       Most  other  XBoard commands are available from the menu bar. The most frequently used commands also have
       shortcut keys or on-screen buttons.  These  shortcut  keystrokes  are  mostly  non-printable  characters.
       Typing  a  letter  or  digit  while the board window has focus will bring up a type-in box with the typed
       letter already in it.  You can use that to type a move in situations where it is your  turn  to  enter  a
       move,  type  a  move  number to call up the position after that move in the display, or, in Edit Position
       mode, type a FEN.  Some rarely used parameters can only be set through options on the command  line  used
       to invoke XBoard.

       XBoard  uses  a settings file, in which it can remember any changes to the settings that are made through
       menus or command-line options, so they will still apply when you restart XBoard for another session.  The
       settings can be saved into this file automatically when XBoard exits, or on explicit request of the user.
       Note that the board window can be sized by the user, but that this will not affect the size of the clocks
       above it, and won't be remembered in the settings file.  To persistently change the size of  the  clocks,
       use  the  `size'  command-line  option  when  starting XBoard.  The default name for the settings file is
       /etc/xboard/xboard.conf, but in a standard install this file is only used as a master settings file  that
       determines  the  system-wide default settings, and defers reading and writing of user settings to a user-
       specific file like ~/.xboardrc in the user's home directory.

       When XBoard is iconized, its graphical icon is a white knight if it is White's  turn  to  move,  a  black
       knight if it is Black's turn.

Chess Servers

       An "Internet Chess Server", or "ICS", is a place on the Internet where people can get  together  to  play
       chess,  watch  other  people's games, or just chat.  You can use either `telnet' or a client program like
       XBoard to connect to the server.  There are thousands of registered users on the different ICS hosts, and
       it is not unusual to meet 200 on both chessclub.com and freechess.org.

       Most people can just type `xboard -ics' to start XBoard as an ICS client.  Invoking XBoard  in  this  way
       connects you to the Internet Chess Club (ICC), a commercial ICS.  You can log in there as a guest even if
       you  do not have a paid account.  To connect to the largest Free ICS (FICS), use the command `xboard -ics
       -icshost freechess.org' instead, or substitute a different host name to connect  to  your  favorite  ICS.
       For  a full description of command-line options that control the connection to ICS and change the default
       values of ICS options, see ICSoptions.

       While you are running XBoard as an ICS client, you use the terminal window that you started  XBoard  from
       as a place to type in commands and read information that is not available on the chessboard.

       The  first  time  you  need  to  use  the terminal is to enter your login name and password, if you are a
       registered player. (You don't need to do this manually; the `icsLogon' option can do it for you.  See ICSoptions.)  If you are not registered, enter `g' as your name, and the server will  pick  a  unique  guest
       name for you.

       Some useful ICS commands include

       help<topic>
              to get help on the given <topic>. To get a list of possible topics type "help" without topic.  Try
              the help command before you ask other people on the server for help.

              For example `help register' tells you how to become a registered ICS player.

       who<flags>
              to  see a list of people who are logged on.  Administrators (people you should talk to if you have
              a problem) are marked with the character `*', an asterisk. The <flags> allow you to  display  only
              selected  players: For example, `who of' shows a list of players who are interested in playing but
              do not have an opponent.

       games  to see what games are being played

       match<player>[<mins>][<inc>]
              to challenge another player to a game. Both opponents get <mins> minutes for the game,  and  <inc>
              seconds  will  be added after each move.  If another player challenges you, the server asks if you
              want to accept the challenge; use the `accept' or `decline' commands to answer.

       acceptdecline
              to accept or decline another player's offer.  The offer may be to start a new game, or to agree to
              a `draw', `adjourn' or `abort' the current game. See ActionMenu.

              If you have more than one pending offer (for example, if more than one player is challenging  you,
              or  if  your  opponent  offers both a draw and to adjourn the game), you have to supply additional
              information, by typing something like `accept <player>', `accept draw', or `draw'.

       drawadjournabort  asks your opponent to terminate a game by mutual  agreement.  Adjourned  games  can  be  continued
              later.   Your opponent can either `decline' your offer or accept it (by typing the same command or
              typing `accept').  In some cases these commands work immediately, without asking your opponent  to
              agree.   For example, you can abort the game unilaterally if your opponent is out of time, and you
              can claim a draw by repetition or the 50-move rule if available simply by typing `draw'.

       finger<player>
              to get information about the given <player>. (Default: yourself.)

       vars   to get a list of personal settings

       set<var><value>
              to modify these settings

       observe<player>
              to observe an ongoing game of the given <player>.

       examineoldmoves
              to review a recently completed game

       Some special XBoard features are activated when you are in examine mode on ICS.  See the descriptions  of
       the  menu  commands  `Forward', `Backward', `Pause', `ICS Client', and `Stop Examining' on the EditMenu,
       ModeMenu, and ActionMenu.

Cmail

       The  `cmail'  program  can  help you play chess by email with opponents of your choice using XBoard as an
       interface.

       You will usually run `cmail' without giving any options.

   CMailoptions-h     Displays `cmail' usage information.

       -c     Shows the conditions of the GNU General Public License.  See Copying.

       -w     Shows the warranty notice of the GNU General Public License.  See Copying.

       -v-xv    Provides or inhibits verbose output from `cmail' and XBoard, useful for debugging. The `-xv'  form
              also inhibits the cmail introduction message.

       -mail-xmail Invokes or inhibits the sending of a mail message containing the move.

       -xboard-xxboard
              Invokes or inhibits the running of XBoard on the game file.

       -reuse-xreuse
              Invokes or inhibits the reuse of an existing XBoard to display the current game.

       -remail
              Resends the last mail message for that game. This inhibits running XBoard.

       -game<name>
              The name of the game to be processed.

       -wgames<number>-bgames<number>-games<number>
              Number  of games to start as White, as Black or in total. Default is 1 as white and none as black.
              If only one color is specified then none of the other color is assumed. If no color  is  specified
              then  equal numbers of White and Black games are started, with the extra game being as White if an
              odd number of total games is specified.

       -me<shortname>-opp<shortname>
              A one-word alias for yourself or your opponent.

       -wname<fullname>-bname<fullname>-myname<fullname>-oppname<fullname>
              The full name of White, Black, yourself or your opponent.

       -wna<netaddress>-bna<netaddress>-na<netaddress>-oppna<netaddress>
              The email address of White, Black, yourself or your opponent.

       -dir<directory>
              The directory in which `cmail'  keeps  its  files.  This  defaults  to  the  environment  variable
              `$CMAIL_DIR'  or  failing  that, `$CHESSDIR', `$HOME/Chess' or `~/Chess'. It will be created if it
              does not exist.

       -arcdir<directory>
              The directory in which `cmail' archives completed games.  Defaults  to  the  environment  variable
              `$CMAIL_ARCDIR' or, in its absence, the same directory as cmail keeps its working files (above).

       -mailprog<mailprogram>
              The  program  used  by  cmail  to  send  email messages. This defaults to the environment variable
              `$CMAIL_MAILPROG' or failing that `/usr/ucb/Mail', `/usr/ucb/mail' or `Mail'. You will need to set
              this variable if none of the above paths fit your system.

       -logFile<file>
              A file in which to dump verbose debugging messages that are invoked with the `-v' option.

       -event<event>
              The PGN Event tag (default `Email correspondence game').

       -site<site>
              The PGN Site tag (default `NET').

       -round<round>
              The PGN Round tag (default `-', not applicable).

       -mode<mode>
              The PGN Mode tag (default `EM', Electronic Mail).

       Otheroptions
              Any option flags not listed above are passed through to XBoard.   Invoking  XBoard  through  CMail
              changes  the  default  values  of  two  XBoard options: The default value for `-noChessProgram' is
              changed to true; that is,  by  default  no  chess  engine  is  started.   The  default  value  for
              `-timeDelay'  is  changed to 0; that is, by default XBoard immediately goes to the end of the game
              as played so far, rather than stepping through the moves one by one.   You  can  still  set  these
              options to whatever values you prefer by supplying them on CMail's command line.  See Options.

   StartingaCMailGame
       Type  `cmail' from a shell to start a game as white. After an opening message, you will be prompted for a
       game name, which is optional -- if you simply press <Enter>, the game name will take  the  form  `you-VS-
       opponent'.  You  will  next  be  prompted for the short name of your opponent. If you haven't played this
       person before, you will also be prompted for his/her email address. `cmail' will then  invoke  XBoard  in
       the  background.  Make your first move and select `Mail Move' from the `File' menu. See FileMenu. If all
       is well, `cmail' will mail a copy of the move to your opponent.  If  you  select  `Exit'  without  having
       selected `Mail Move' then no move will be made.

   AnsweringaMove
       When  you  receive  a  message  from  an opponent containing a move in one of your games, simply pipe the
       message through `cmail'. In some mailers this is as simple as typing `| cmail' when viewing the  message,
       while  in others you may have to save the message to a file and do `cmail < file' at the command line. In
       either case `cmail' will display the game using XBoard. If you didn't exit  XBoard  when  you  made  your
       first  move  then  `cmail'  will do its best to use the existing XBoard instead of starting a new one. As
       before, simply make a move and select `Mail Move' from the `File' menu. See FileMenu. `cmail'  will  try
       to use the XBoard that was most recently used to display the current game. This means that many games can
       be in progress simultaneously, each with its own active XBoard.

       If  you  want to look at the history or explore a variation, go ahead, but you must return to the current
       position before XBoard will allow you to mail a move. If you edit the  game's  history  you  must  select
       `Reload Same Game' from the `File' menu to get back to the original position, then make the move you want
       and select `Mail Move'.  As before, if you decide you aren't ready to make a move just yet you can either
       select `Exit' without sending a move or just leave XBoard running until you are ready.

   Multi-GameMessages
       It  is  possible  to  have  a  `cmail' message carry more than one game.  This feature was implemented to
       handle IECG (International Email Chess Group) matches, where a match consists of one game  as  white  and
       one  as black, with moves transmitted simultaneously. In case there are more general uses, `cmail' itself
       places no limit on the number of black/white games contained in a message; however, XBoard does.

   CompletingaGame
       Because XBoard can detect checkmate and stalemate, `cmail' handles game termination sensibly. As well  as
       resignation, the `Action' menu allows draws to be offered and accepted for `cmail' games.

       For multi-game messages, only unfinished and just-finished games will be included in email messages. When
       all  the  games  are  finished,  they  are archived in the user's archive directory, and similarly in the
       opponent's when he or she pipes the final message through `cmail'. The archive  file  name  includes  the
       date the game was started.

   KnownCMailProblems
       It's  possible  that  a  strange conjunction of conditions may occasionally mean that `cmail' has trouble
       reactivating an existing XBoard. If this should happen, simply trying it  again  should  work.   If  not,
       remove the file that stores the XBoard's PID (`game.pid') or use the `-xreuse' option to force `cmail' to
       start a new XBoard.

       Versions  of  `cmail'  after 2.16 no longer understand the old file format that XBoard used to use and so
       cannot be used to correspond with anyone using an older version.

       Versions of `cmail' older than 2.11 do not handle multi-game messages, so  multi-game  correspondence  is
       not possible with opponents using an older version.

Description

       XBoard is a graphical chessboard that can serve as a user interface to chess engines (such as GNU Chess),
       the Internet Chess Servers, electronic mail correspondence chess, or your own collection of saved games.

       This manual documents version 4.9.1 of XBoard.

Environment Variables

       Game and position files are found in a directory named by the `CHESSDIR' environment  variable.  If  this
       variable is not set, the current working directory is used. If `CHESSDIR' is set, XBoard actually changes
       its working directory to `$CHESSDIR', so any files written by the chess engine will be placed there too.

Firewalls

       By default, XBoard communicates with an Internet Chess Server by opening a TCP socket directly  from  the
       machine  it is running on to the ICS. If there is a firewall between your machine and the ICS, this won't
       work. Here are some recipes for getting around common kinds of firewalls using special options to XBoard.
       Important: See the paragraph in the below about extra echoes, in Limitations.

       Suppose that you can't telnet directly to ICS, but you can telnet to a firewall host, log  in,  and  then
       telnet  from  there  to  ICS.   Let's say the firewall is called `firewall.example.com'. Set command-line
       options as follows:

           xboard -ics -icshost firewall.example.com -icsport 23

       Then when you run XBoard in ICS mode, you will be prompted to log in to the  firewall  host.  This  works
       because  port  23  is  the standard telnet login service. Do so, then telnet to ICS, using a command like
       `telnet chessclub.com 5000', or whatever command the firewall provides for telnetting to port 5000.

       If your firewall lets you telnet (or rlogin) to remote hosts but doesn't let you telnet to port 5000, you
       may be able to connect to the chess server on port 23 instead, which is the port the telnet program  uses
       by  default.   Some chess servers support this (including chessclub.com and freechess.org), while some do
       not.

       If your chess server does not allow connections on port 23 and  your  firewall  does  not  allow  you  to
       connect  to  other ports, you may be able to connect by hopping through another host outside the firewall
       that you have an account on.  For instance, suppose you have a shell account  at  `foo.edu'.  Follow  the
       recipe  above,  but  instead of typing `telnet chessclub.com 5000' to the firewall, type `telnet foo.edu'
       (or `rlogin foo.edu'), log in there, and then type `telnet chessclub.com 5000'.

       Suppose that you can't telnet directly to ICS, but you can use rsh to run programs on  a  firewall  host,
       and  that  host  can telnet to ICS.  Let's say the firewall is called `rsh.example.com'. Set command-line
       options as follows:

           xboard -ics -gateway rsh.example.com -icshost chessclub.com

       Then when you run XBoard in ICS mode, it will connect to the ICS  by  using  `rsh'  to  run  the  command
       `telnet chessclub.com 5000' on host `rsh.example.com'.

       Suppose  that you can telnet anywhere you want, but you have to run a special program called `ptelnet' to
       do so.

       First, we'll consider the easy case, in which `ptelnet chessclub.com 5000' gets you to the chess  server.
       In this case set command line options as follows:

           xboard -ics -telnet -telnetProgram ptelnet

       Then  when  you run XBoard in ICS mode, it will issue the command `ptelnet chessclub.com 5000' to connect
       to the ICS.

       Next, suppose that `ptelnet chessclub.com 5000' doesn't work; that is, your `ptelnet' program doesn't let
       you connect to alternative ports. As noted above, your chess server may allow you to connect on  port  23
       instead.  In that case, just add the option `-icsport ""' to the above command.  But if your chess server
       doesn't  let  you  connect on port 23, you will have to find some other host outside the firewall and hop
       through it. For instance, suppose you have a shell account at `foo.edu'.  Set  command  line  options  as
       follows:

           xboard -ics -telnet -telnetProgram ptelnet -icshost foo.edu -icsport ""

       Then  when  you  run  XBoard  in ICS mode, it will issue the command `ptelnet foo.edu' to connect to your
       account at `foo.edu'. Log in there, then type `telnet chessclub.com 5000'.

       ICC timestamp and FICS timeseal do not work through some firewalls.   You  can  use  them  only  if  your
       firewall  gives  a  clean TCP connection with a full 8-bit wide path.  If your firewall allows you to get
       out only by running a special telnet program, you can't use timestamp or timeseal across it.  But if  you
       have access to a computer just outside your firewall, and you have much lower netlag when talking to that
       computer  than to the ICS, it might be worthwhile running timestamp there.  Follow the instructions above
       for hopping through a host outside the firewall (foo.edu in the example), but run timestamp  or  timeseal
       on that host instead of telnet.

       Suppose  that you have a SOCKS firewall that will give you a clean 8-bit wide TCP connection to the chess
       server, but only after you authenticate yourself via the SOCKS protocol.  In that case, you could make  a
       socksified  version of XBoard and run that.  If you are using timestamp or timeseal, you will to socksify
       it, not XBoard; this may be difficult seeing that ICC and FICS do  not  provide  source  code  for  these
       programs.   Socksification  is  beyond  the  scope  of  this  document,  but  see  the  SOCKS Web site at
       http://www.socks.permeo.com/.  If you are missing SOCKS, try http://www.funbureau.com/.

Gnu General Public License

       Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/'

       Everyone is permitted to copy and distribute verbatim copies of this
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              without modification), making available to the public, and in some countries other  activities  as
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              To  ``convey''  a work means any kind of propagation that enables other parties to make or receive
              copies.  Mere interaction with a user through a computer network, with no transfer of a  copy,  is
              not conveying.

              An  interactive  user  interface  displays  ``Appropriate  Legal  Notices''  to the extent that it
              includes a convenient and prominently visible feature that (1) displays an  appropriate  copyright
              notice,  and  (2) tells the user that there is no warranty for the work (except to the extent that
              warranties are provided), that licensees may convey the work under this License, and how to view a
              copy of this License.  If the interface presents a list of user commands or  options,  such  as  a
              menu, a prominent item in the list meets this criterion.

       SourceCode.
              The  ``source  code''  for a work means the preferred form of the work for making modifications to
              it.  ``Object code'' means any non-source form of a work.

              A ``Standard Interface'' means an interface that either is  an  official  standard  defined  by  a
              recognized  standards  body,  or, in the case of interfaces specified for a particular programming
              language, one that is widely used among developers working in that language.

              The ``System Libraries'' of an executable work include anything, other than the work as  a  whole,
              that  (a)  is included in the normal form of packaging a Major Component, but which is not part of
              that Major Component, and (b) serves only to enable use of the work with that Major Component,  or
              to implement a Standard Interface for which an implementation is available to the public in source
              code  form.   A  ``Major  Component'', in this context, means a major essential component (kernel,
              window system, and so on) of the specific operating system (if any) on which the  executable  work
              runs, or a compiler used to produce the work, or an object code interpreter used to run it.

              The  ``Corresponding  Source''  for a work in object code form means all the source code needed to
              generate, install, and (for an executable work) run the  object  code  and  to  modify  the  work,
              including  scripts  to  control  those activities.  However, it does not include the work's System
              Libraries, or general-purpose tools or generally available free programs which are used unmodified
              in performing those activities but which are not part of the  work.   For  example,  Corresponding
              Source  includes  interface  definition  files  associated with source files for the work, and the
              source code for shared libraries and dynamically linked subprograms that the work is  specifically
              designed  to  require,  such  as  by  intimate  data  communication  or control flow between those
              subprograms and other parts of the work.

              The Corresponding Source need not include anything that users can  regenerate  automatically  from
              other parts of the Corresponding Source.

              The Corresponding Source for a work in source code form is that same work.

       BasicPermissions.
              All  rights  granted  under this License are granted for the term of copyright on the Program, and
              are irrevocable provided the stated conditions are met.   This  License  explicitly  affirms  your
              unlimited  permission  to  run  the unmodified Program.  The output from running a covered work is
              covered by this License only if the output, given its content, constitutes a covered  work.   This
              License acknowledges your rights of fair use or other equivalent, as provided by copyright law.

              You  may  make, run and propagate covered works that you do not convey, without conditions so long
              as your license otherwise remains in force.  You may convey covered works to others for  the  sole
              purpose  of having them make modifications exclusively for you, or provide you with facilities for
              running those works, provided that you comply with the terms of  this  License  in  conveying  all
              material  for  which you do not control copyright.  Those thus making or running the covered works
              for you must do so exclusively on your behalf, under your direction and  control,  on  terms  that
              prohibit  them from making any copies of your copyrighted material outside their relationship with
              you.

              Conveying under any other circumstances is permitted solely under  the  conditions  stated  below.
              Sublicensing is not allowed; section 10 makes it unnecessary.

       ProtectingUsers'LegalRightsFromAnti-CircumventionLaw.
              No  covered  work  shall be deemed part of an effective technological measure under any applicable
              law fulfilling obligations under article 11 of the WIPO copyright treaty adopted  on  20  December
              1996, or similar laws prohibiting or restricting circumvention of such measures.

              When you convey a covered work, you waive any legal power to forbid circumvention of technological
              measures to the extent such circumvention is effected by exercising rights under this License with
              respect  to the covered work, and you disclaim any intention to limit operation or modification of
              the work as a means of enforcing, against the work's users, your or third parties' legal rights to
              forbid circumvention of technological measures.

       ConveyingVerbatimCopies.
              You may convey verbatim copies of the Program's source code as you  receive  it,  in  any  medium,
              provided  that  you  conspicuously and appropriately publish on each copy an appropriate copyright
              notice; keep intact all notices stating that this License and any non-permissive  terms  added  in
              accord  with  section 7 apply to the code; keep intact all notices of the absence of any warranty;
              and give all recipients a copy of this License along with the Program.

              You may charge any price or no price for each copy that you convey, and you may offer  support  or
              warranty protection for a fee.

       ConveyingModifiedSourceVersions.
              You  may  convey a work based on the Program, or the modifications to produce it from the Program,
              in the form of source code under the terms of section 4, provided that you also meet all of  these
              conditions:

              The work must carry prominent notices stating that you modified it, and giving a relevant date.

              The  work  must  carry  prominent  notices  stating that it is released under this License and any
              conditions added under section 7.  This requirement modifies  the  requirement  in  section  4  to
              ``keep intact all notices''.

              You  must  license  the  entire  work,  as  a  whole,  under this License to anyone who comes into
              possession of a copy.  This License will therefore apply, along  with  any  applicable  section  7
              additional  terms,  to  the  whole  of  the  work,  and  all its parts, regardless of how they are
              packaged.  This License gives no permission to license the work in any other way, but it does  not
              invalidate such permission if you have separately received it.

              If the work has interactive user interfaces, each must display Appropriate Legal Notices; however,
              if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work
              need not make them do so.

              A  compilation of a covered work with other separate and independent works, which are not by their
              nature extensions of the covered work, and which are not combined with it such as to form a larger
              program, in or on a volume of a storage or distribution medium, is called an ``aggregate'' if  the
              compilation  and  its  resulting copyright are not used to limit the access or legal rights of the
              compilation's users beyond what the individual works permit.  Inclusion of a covered  work  in  an
              aggregate does not cause this License to apply to the other parts of the aggregate.

       ConveyingNon-SourceForms.
              You  may  convey  a covered work in object code form under the terms of sections 4 and 5, provided
              that you also convey the machine-readable Corresponding Source under the terms of this License, in
              one of these ways:

              Convey the object code in, or embodied in, a physical product (including a  physical  distribution
              medium),  accompanied  by  the Corresponding Source fixed on a durable physical medium customarily
              used for software interchange.

              Convey the object code in, or embodied in, a physical product (including a  physical  distribution
              medium),  accompanied  by a written offer, valid for at least three years and valid for as long as
              you offer spare parts or customer support for that product model, to give anyone who possesses the
              object code either (1) a copy of the Corresponding Source for all the software in the product that
              is covered  by  this  License,  on  a  durable  physical  medium  customarily  used  for  software
              interchange, for a price no more than your reasonable cost of physically performing this conveying
              of source, or (2) access to copy the Corresponding Source from a network server at no charge.

              Convey  individual  copies  of  the  object  code  with a copy of the written offer to provide the
              Corresponding Source.  This alternative is allowed only occasionally and noncommercially, and only
              if you received the object code with such an offer, in accord with subsection 6b.

              Convey the object code by offering access from a designated place (gratis or for  a  charge),  and
              offer  equivalent  access to the Corresponding Source in the same way through the same place at no
              further charge.  You need not require recipients to copy the Corresponding Source along  with  the
              object  code.   If the place to copy the object code is a network server, the Corresponding Source
              may be on a different server (operated by you or a third party) that supports  equivalent  copying
              facilities,  provided  you  maintain clear directions next to the object code saying where to find
              the Corresponding Source.  Regardless of what server hosts the Corresponding  Source,  you  remain
              obligated to ensure that it is available for as long as needed to satisfy these requirements.

              Convey  the object code using peer-to-peer transmission, provided you inform other peers where the
              object code and Corresponding Source of the work are being offered to the  general  public  at  no
              charge under subsection 6d.

              A  separable  portion  of  the  object  code, whose source code is excluded from the Corresponding
              Source as a System Library, need not be included in conveying the object code work.

              A ``User Product'' is either (1)  a  ``consumer  product'',  which  means  any  tangible  personal
              property  which  is  normally  used  for  personal, family, or household purposes, or (2) anything
              designed or sold for incorporation into a  dwelling.   In  determining  whether  a  product  is  a
              consumer product, doubtful cases shall be resolved in favor of coverage.  For a particular product
              received  by  a particular user, ``normally used'' refers to a typical or common use of that class
              of product, regardless of the status of the particular user or of the way in which the  particular
              user  actually  uses,  or  expects  or  is  expected to use, the product.  A product is a consumer
              product regardless of whether the product has substantial commercial, industrial  or  non-consumer
              uses, unless such uses represent the only significant mode of use of the product.

              ``Installation Information'' for a User Product means any methods, procedures, authorization keys,
              or  other  information required to install and execute modified versions of a covered work in that
              User Product from a modified version of its Corresponding Source.  The information must suffice to
              ensure that the continued functioning of the modified object code  is  in  no  case  prevented  or
              interfered with solely because modification has been made.

              If  you  convey  an object code work under this section in, or with, or specifically for use in, a
              User Product, and the conveying occurs as part of a transaction in which the right  of  possession
              and  use  of  the  User  Product is transferred to the recipient in perpetuity or for a fixed term
              (regardless of how the transaction is characterized), the Corresponding Source conveyed under this
              section must be accompanied by the Installation Information.  But this requirement does not  apply
              if neither you nor any third party retains the ability to install modified object code on the User
              Product (for example, the work has been installed in ROM).

              The  requirement to provide Installation Information does not include a requirement to continue to
              provide support service, warranty, or updates for a work that has been modified  or  installed  by
              the  recipient,  or  for the User Product in which it has been modified or installed.  Access to a
              network may be denied when the modification itself materially and adversely affects the  operation
              of the network or violates the rules and protocols for communication across the network.

              Corresponding  Source conveyed, and Installation Information provided, in accord with this section
              must be in a format that is publicly documented (and  with  an  implementation  available  to  the
              public in source code form), and must require no special password or key for unpacking, reading or
              copying.

       AdditionalTerms.
              ``Additional  permissions''  are  terms  that  supplement  the  terms  of  this  License by making
              exceptions from one or more of its conditions.  Additional permissions that are applicable to  the
              entire  Program  shall be treated as though they were included in this License, to the extent that
              they are valid under applicable law.  If additional permissions apply only to part of the Program,
              that part may be used separately under those permissions, but the entire Program remains  governed
              by this License without regard to the additional permissions.

              When you convey a copy of a covered work, you may at your option remove any additional permissions
              from  that  copy, or from any part of it.  (Additional permissions may be written to require their
              own removal in certain cases when you modify the work.)  You may place additional  permissions  on
              material,  added  by  you  to a covered work, for which you have or can give appropriate copyright
              permission.

              Notwithstanding any other provision of this License, for material you add to a covered  work,  you
              may (if authorized by the copyright holders of that material) supplement the terms of this License
              with terms:

              Disclaiming  warranty  or  limiting  liability differently from the terms of sections 15 and 16 of
              this License; or

              Requiring preservation of specified reasonable  legal  notices  or  author  attributions  in  that
              material or in the Appropriate Legal Notices displayed by works containing it; or

              Prohibiting  misrepresentation of the origin of that material, or requiring that modified versions
              of such material be marked in reasonable ways as different from the original version; or

              Limiting the use for publicity purposes of names of licensors or authors of the material; or

              Declining to grant rights under trademark law for use of some trade names, trademarks, or  service
              marks; or

              Requiring  indemnification  of  licensors  and  authors of that material by anyone who conveys the
              material (or modified versions of it) with contractual assumptions of liability to the  recipient,
              for  any  liability  that  these  contractual  assumptions  directly impose on those licensors and
              authors.

              All other non-permissive additional terms  are  considered  ``further  restrictions''  within  the
              meaning  of  section  10.  If the Program as you received it, or any part of it, contains a notice
              stating that it is governed by this License along with a term that is a further  restriction,  you
              may  remove  that  term.   If  a  license  document  contains  a  further  restriction but permits
              relicensing or conveying under this License, you may add to a covered work  material  governed  by
              the  terms  of  that license document, provided that the further restriction does not survive such
              relicensing or conveying.

              If you add terms to a covered work in accord with this section, you must place,  in  the  relevant
              source  files,  a  statement  of  the  additional  terms  that  apply  to those files, or a notice
              indicating where to find the applicable terms.

              Additional terms, permissive or non-permissive, may be stated in the form of a separately  written
              license, or stated as exceptions; the above requirements apply either way.

       Termination.
              You  may  not  propagate or modify a covered work except as expressly provided under this License.
              Any attempt otherwise to propagate or modify it is void, and  will  automatically  terminate  your
              rights  under  this  License  (including  any patent licenses granted under the third paragraph of
              section 11).

              However, if you cease all violation of this License, then your license from a particular copyright
              holder is reinstated (a) provisionally, unless and  until  the  copyright  holder  explicitly  and
              finally  terminates your license, and (b) permanently, if the copyright holder fails to notify you
              of the violation by some reasonable means prior to 60 days after the cessation.

              Moreover, your license from a  particular  copyright  holder  is  reinstated  permanently  if  the
              copyright  holder  notifies  you of the violation by some reasonable means, this is the first time
              you have received notice of violation of this License (for any work) from that  copyright  holder,
              and you cure the violation prior to 30 days after your receipt of the notice.

              Termination  of your rights under this section does not terminate the licenses of parties who have
              received copies or rights from you under this License.  If your rights have  been  terminated  and
              not permanently reinstated, you do not qualify to receive new licenses for the same material under
              section 10.

       AcceptanceNotRequiredforHavingCopies.
              You  are  not  required  to  accept this License in order to receive or run a copy of the Program.
              Ancillary propagation of a covered work occurring solely as a consequence  of  using  peer-to-peer
              transmission  to receive a copy likewise does not require acceptance.  However, nothing other than
              this License grants you permission to  propagate  or  modify  any  covered  work.   These  actions
              infringe  copyright  if  you do not accept this License.  Therefore, by modifying or propagating a
              covered work, you indicate your acceptance of this License to do so.

       AutomaticLicensingofDownstreamRecipients.
              Each time you convey a covered work, the recipient  automatically  receives  a  license  from  the
              original  licensors, to run, modify and propagate that work, subject to this License.  You are not
              responsible for enforcing compliance by third parties with this License.

              An  ``entity  transaction''  is  a  transaction  transferring  control  of  an  organization,   or
              substantially  all  assets  of  one, or subdividing an organization, or merging organizations.  If
              propagation of a covered work results from an entity transaction, each party to  that  transaction
              who  receives  a  copy  of  the  work  also  receives  whatever  licenses  to the work the party's
              predecessor in interest had or could give under the previous paragraph, plus a right to possession
              of the Corresponding Source of the work from the predecessor in interest, if the  predecessor  has
              it or can get it with reasonable efforts.

              You  may  not  impose  any  further restrictions on the exercise of the rights granted or affirmed
              under this License.  For example, you may not impose a license fee, royalty, or other  charge  for
              exercise  of  rights  granted under this License, and you may not initiate litigation (including a
              cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed  by  making,
              using, selling, offering for sale, or importing the Program or any portion of it.

       Patents.
              A  ``contributor'' is a copyright holder who authorizes use under this License of the Program or a
              work on which the  Program  is  based.   The  work  thus  licensed  is  called  the  contributor's
              ``contributor version''.

              A  contributor's  ``essential  patent  claims''  are  all patent claims owned or controlled by the
              contributor, whether already acquired or hereafter acquired,  that  would  be  infringed  by  some
              manner,  permitted  by  this License, of making, using, or selling its contributor version, but do
              not include claims that would be infringed only as a consequence of further  modification  of  the
              contributor  version.   For  purposes  of this definition, ``control'' includes the right to grant
              patent sublicenses in a manner consistent with the requirements of this License.

              Each contributor grants you a non-exclusive, worldwide,  royalty-free  patent  license  under  the
              contributor's  essential  patent  claims, to make, use, sell, offer for sale, import and otherwise
              run, modify and propagate the contents of its contributor version.

              In the following three paragraphs, a ``patent license'' is any express  agreement  or  commitment,
              however  denominated,  not to enforce a patent (such as an express permission to practice a patent
              or covenant not to sue for patent infringement).  To ``grant'' such a patent license  to  a  party
              means to make such an agreement or commitment not to enforce a patent against the party.

              If  you convey a covered work, knowingly relying on a patent license, and the Corresponding Source
              of the work is not available for anyone to copy, free of  charge  and  under  the  terms  of  this
              License,  through  a publicly available network server or other readily accessible means, then you
              must either (1) cause the Corresponding Source to be so  available,  or  (2)  arrange  to  deprive
              yourself  of  the  benefit  of  the  patent license for this particular work, or (3) arrange, in a
              manner consistent with the  requirements  of  this  License,  to  extend  the  patent  license  to
              downstream  recipients.   ``Knowingly  relying'' means you have actual knowledge that, but for the
              patent license, your conveying the covered work in a country,  or  your  recipient's  use  of  the
              covered  work  in  a country, would infringe one or more identifiable patents in that country that
              you have reason to believe are valid.

              If, pursuant to or in connection  with  a  single  transaction  or  arrangement,  you  convey,  or
              propagate  by  procuring  conveyance of, a covered work, and grant a patent license to some of the
              parties receiving the covered work authorizing them to use, propagate, modify or convey a specific
              copy of the covered work, then the patent license you  grant  is  automatically  extended  to  all
              recipients of the covered work and works based on it.

              A  patent  license  is ``discriminatory'' if it does not include within the scope of its coverage,
              prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that
              are specifically granted under this License.  You may not convey a covered work if you are a party
              to an arrangement with a third party that is in the business of distributing software, under which
              you make payment to the third party based on the extent of your activity of  conveying  the  work,
              and  under  which the third party grants, to any of the parties who would receive the covered work
              from you, a discriminatory patent license (a) in  connection  with  copies  of  the  covered  work
              conveyed  by  you  (or copies made from those copies), or (b) primarily for and in connection with
              specific products or compilations that contain the covered work,  unless  you  entered  into  that
              arrangement, or that patent license was granted, prior to 28 March 2007.

              Nothing  in  this License shall be construed as excluding or limiting any implied license or other
              defenses to infringement that may otherwise be available to you under applicable patent law.

       NoSurrenderofOthers'Freedom.
              If conditions are imposed on you (whether by court order, agreement or otherwise) that  contradict
              the  conditions  of  this License, they do not excuse you from the conditions of this License.  If
              you cannot convey a covered work so as to  satisfy  simultaneously  your  obligations  under  this
              License  and  any other pertinent obligations, then as a consequence you may not convey it at all.
              For example, if you agree to terms that obligate you to collect a royalty  for  further  conveying
              from  those  to  whom  you convey the Program, the only way you could satisfy both those terms and
              this License would be to refrain entirely from conveying the Program.

       UsewiththeGNUAfferoGeneralPublicLicense.
              Notwithstanding any other provision of this License, you have permission to link  or  combine  any
              covered  work with a work licensed under version 3 of the GNU Affero General Public License into a
              single combined work, and to convey the resulting work.  The terms of this License  will  continue
              to  apply  to  the  part which is the covered work, but the special requirements of the GNU Affero
              General Public License, section 13, concerning interaction through a network  will  apply  to  the
              combination as such.

       RevisedVersionsofthisLicense.
              The  Free  Software  Foundation  may publish revised and/or new versions of the GNU General Public
              License from time to time.  Such new versions will be similar in spirit to  the  present  version,
              but may differ in detail to address new problems or concerns.

              Each  version  is  given a distinguishing version number.  If the Program specifies that a certain
              numbered version of the GNU General Public License ``or any later version''  applies  to  it,  you
              have  the  option  of following the terms and conditions either of that numbered version or of any
              later version published by the Free Software Foundation.   If  the  Program  does  not  specify  a
              version number of the GNU General Public License, you may choose any version ever published by the
              Free Software Foundation.

              If  the  Program specifies that a proxy can decide which future versions of the GNU General Public
              License can be used, that  proxy's  public  statement  of  acceptance  of  a  version  permanently
              authorizes you to choose that version for the Program.

              Later  license  versions may give you additional or different permissions.  However, no additional
              obligations are imposed on any author or copyright holder as a result of your choosing to follow a
              later version.

       DisclaimerofWarranty.
              THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED  BY  APPLICABLE  LAW.   EXCEPT  WHEN
              OTHERWISE  STATED  IN  WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM ``AS
              IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
              IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO
              THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE  DEFECTIVE,  YOU
              ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

       LimitationofLiability.
              IN  NO  EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER,
              OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE  LIABLE  TO  YOU
              FOR  DAMAGES,  INCLUDING  ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF
              THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR  DATA  BEING
              RENDERED  INACCURATE  OR  LOSSES  SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO
              OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER  PARTY  HAS  BEEN  ADVISED  OF  THE
              POSSIBILITY OF SUCH DAMAGES.

       InterpretationofSections15and16.
              If  the  disclaimer  of  warranty and limitation of liability provided above cannot be given local
              legal effect according to their terms, reviewing courts shall apply local law  that  most  closely
              approximates  an  absolute  waiver of all civil liability in connection with the Program, unless a
              warranty or assumption of liability accompanies a copy of the Program in return for a fee.

              If you develop a new program, and you want it to be of the greatest possible use  to  the  public,
              the  best  way  to  achieve  this  is to make it free software which everyone can redistribute and
              change under these terms.

              To do so, attach the following notices to the program.  It is safest to attach them to  the  start
              of each source file to most effectively state the exclusion of warranty; and each file should have
              at least the ``copyright'' line and a pointer to where the full notice is found.

              ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
              Copyright (C) YEAR NAME OF AUTHOR

              This program is free software: you can redistribute it and/or modify
              it under the terms of the GNU General Public License as published by
              the Free Software Foundation, either version 3 of the License, or (at
              your option) any later version.

              This program is distributed in the hope that it will be useful, but
              WITHOUT ANY WARRANTY; without even the implied warranty of
              MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
              General Public License for more details.

              You should have received a copy of the GNU General Public License
              along with this program.  If not, see `http://www.gnu.org/licenses/'.

              Also add information on how to contact you by electronic and paper mail.

              If  the  program does terminal interaction, make it output a short notice like this when it starts
              in an interactive mode:

              PROGRAM Copyright (C) YEAR NAME OF AUTHOR
              This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
              This is free software, and you are welcome to redistribute it
              under certain conditions; type `show c' for details.

              The hypothetical commands `show w' and `show c' should show the appropriate parts of  the  General
              Public  License.   Of course, your program's commands might be different; for a GUI interface, you
              would use an ``about box''.

              You should also get your employer (if you work as a programmer) or  school,  if  any,  to  sign  a
              ``copyright  disclaimer'' for the program, if necessary.  For more information on this, and how to
              apply and follow the GNU GPL, see `http://www.gnu.org/licenses/'.

              The GNU General Public License  does  not  permit  incorporating  your  program  into  proprietary
              programs.   If  your  program  is  a subroutine library, you may consider it more useful to permit
              linking proprietary applications with the library.  If this is what you want to do,  use  the  GNU
              Lesser   General   Public   License   instead   of   this   License.    But   first,  please  read
              `http://www.gnu.org/philosophy/why-not-lgpl.html'.

GNU                                                  $Date:                                            xboard(6)

Limitations And Known Bugs

       There  is  no  way  for  two  people running copies of XBoard to play each other without going through an
       Internet Chess Server.

       Under some circumstances, your ICS password may be echoed when you log on.

       If you are connecting to the ICS by running telnet on an Internet provider or firewall host, you may find
       that each line you type is echoed back an extra time after you hit <Enter>. If your Internet provider  is
       a  Unix system, you can probably turn its echo off by typing `stty -echo' after you log in, and/or typing
       <^E><Enter> (Ctrl+E followed by the Enter key) to the telnet program after you have logged into ICS.   It
       is  a  good  idea to do this if you can, because the extra echo can occasionally confuse XBoard's parsing
       routines.

       The game parser recognizes only algebraic notation.

       Many of the following points used to be limitations in XBoard 4.2.7 and earlier, but are now  fixed:  The
       internal  move  legality  tester  in  XBoard  4.3.xx does look at the game history, and is fully aware of
       castling or en-passant-capture rights. It permits castling with the king on the d file  because  this  is
       possible  in  some  "wild 1" games on ICS.  The piece-drop menu does not check piece drops in bughouse to
       see if you actually hold the piece you are trying to drop. But this way  of  dropping  pieces  should  be
       considered  an obsolete feature, now that pieces can be dropped by dragging them from the holdings to the
       board. Anyway, if you would attempt an illegal move when using a chess engine or  the  ICS,  XBoard  will
       accept the error message that comes back, undo the move, and let you try another.  FEN positions saved by
       XBoard do include correct information about whether castling or en passant are legal, and also handle the
       50-move  counter.   The  mate  detector  does  not understand that non-contact mate is not really mate in
       bughouse.  The only problem this causes while playing is minor: a "#"  (mate  indicator)  character  will
       show up after a non-contact mating move in the move list. XBoard will not assume the game is over at that
       point, not even when the option Detect Mates is on.  Edit Game mode always uses the rules of the selected
       variant,  which  can  be a variant that uses piece drops.  You can load and edit games that contain piece
       drops.  The (obsolete) piece menus are not active, but you can perform piece  drops  by  dragging  pieces
       from the holdings.  Fischer Random castling is fully understood.  You can enter castlings by dragging the
       King  on  top  of  your  Rook.   You  can probably also play Fischer Random successfully on ICS by typing
       castling moves into the ICS Interaction window.

       The menus may not work if your keyboard is in Caps Lock or Num Lock mode.  This seems  to  be  a  problem
       with the Athena menu widget, not an XBoard bug.

       Also  see  the  ToDo  file  included with the distribution for many other possible bugs, limitations, and
       ideas for improvement that have been suggested.

Major Modes

       XBoard  always runs in one of four major modes.  You select the major mode from the command line when you
       start up XBoard.

       xboard[options]
              As an interface to GNU Chess or another chess engine running on your machine, XBoard lets you play
              a game against the machine, set up arbitrary positions, force variations, watch a game between two
              chess engines, interactively analyze your stored games or set up and analyze arbitrary  positions.
              To  run  engines  that  use  the  UCI  standard  XBoard  will draw upon the Polyglot adapter fully
              transparently, but you will need to have the polyglot package installed for this to work.

       xboard-ics-icshosthostname[options]
              As Internet Chess Server (ICS) interface, XBoard lets you play against other  ICS  users,  observe
              games they are playing, or review games that have recently finished.  Most of the ICS "wild" chess
              variants are supported, including bughouse.

       xboard-ncp[options]
              XBoard can also be used simply as an electronic chessboard to play through games. It will read and
              write game files and allow you to play through variations manually. You can use it to browse games
              off the net or review games you have saved.  These features are also available in the other modes.

       |pxboard
              If you want to pipe games into XBoard, use the supplied shell script `pxboard'.  For example, from
              the  news  reader  `xrn',  find a message with one or more games in it, click the Save button, and
              type `|pxboard' as the file name.

       cmail[options]
              As an interface to electronic mail correspondence chess, XBoard works with the cmail program.  See
              CMail below for instructions.

Name

       xboard - X graphical user interface for chess

Options

       This section documents the command-line options to XBoard.  You can set these options  in  two  ways:  by
       typing  them  on the shell command line you use to start XBoard, or by editing the settings file (usually
       ~/.xboardrc) to alter the value of the setting that was saved there.   Some  of  the  options  cannot  be
       changed  while  XBoard  is  running;  others  set the initial state of items that can be changed with the
       Options menu.

       Most of the options have both a long name and a short name. To turn a boolean option on or off  from  the
       command  line, either give its long name followed by the value true or false (`-longOptionName true'), or
       give just the short name to turn the option on (`-opt'), or the short name preceded by `x'  to  turn  the
       option  off  (`-xopt'). For options that take strings or numbers as values, you can use the long or short
       option names interchangeably.

   ChessEngineOptions-tcor-timeControlminutes[:seconds]
              Each player begins with his clock set to the  `timeControl'  period.   Default:  5  minutes.   The
              additional options `movesPerSession' and `timeIncrement' are mutually exclusive.

       -mpsor-movesPerSessionmoves
              When  both  players have made `movesPerSession' moves, a new `timeControl' period is added to both
              clocks.  Default: 40 moves.

       -incor-timeIncrementseconds
              If this option is specified, `movesPerSession' is ignored.  Instead,  after  each  player's  move,
              `timeIncrement'  seconds  are  added to his clock.  Use `-inc 0' if you want to require the entire
              game to be played in one `timeControl' period, with no increment.  Default:  -1,  which  specifies
              `movesPerSession' mode.

       -clock/-xclockor-clockModetrue/false
              Determines  whether  or not to display the chess clocks. If clockMode is false, the clocks are not
              shown, but the side that is to play next is still highlighted. Also, unless `searchTime'  is  set,
              the chess engine still keeps track of the clock time and uses it to determine how fast to make its
              moves.

       -shoMoveTimetrue/false
              When  this  option  is set the time that has been thought about the current move will be displayed
              behind the remaining time in parentheses (in seconds).  Default: false.

       -stor-searchTimeminutes[:seconds]
              Tells the chess engine to spend at most the given amount of time searching for each of its  moves.
              Without  this  option,  the  chess engine chooses its search time based on the number of moves and
              amount of time remaining until the next time control.  Setting this option also sets clockMode  to
              false.

       -depthor-searchDepthnumber
              Tells  the  chess engine to look ahead at most the given number of moves when searching for a move
              to make. Without this option, the chess engine chooses its search depth based  on  the  number  of
              moves  and amount of time remaining until the next time control.  With the option, the engine will
              cut off its search early if it reaches the specified depth.

       -firstNPSnumber-secondNPSnumber
              Tells the chess engine to use an internal time standard based on its node count, rather then wall-
              clock time, to make its timing decisions.  The time in  virtual  seconds  should  be  obtained  by
              dividing  the node count through the given number, like the number was a rate in nodes per second.
              Xboard will manage the clocks in accordance with this, relying on the number of nodes reported  by
              the  engine  in its thinking output. If the given number equals zero, it can obviously not be used
              to convert nodes to seconds, and the time reported by the engine is used to decrement  the  XBoard
              clock in stead. The engine is supposed to report in CPU time it uses, rather than wall-clock time,
              in  this  mode.  This  option  can  provide fairer conditions for engine-engine matches on heavily
              loaded machines, or with very fast games (where the wall clock is too inaccurate).  `showThinking'
              must be on for this option to work. Default: -1 (off).  Not many engines might support this yet!

       -firstTimeOddsfactor-secondTimeOddsfactor
              Reduces the time given to the mentioned engine by the given factor.   If  pondering  is  off,  the
              effect  is indistinguishable from what would happen if the engine was running on an n-times slower
              machine. Default: 1.

       -timeOddsModemode
              This option determines how the case is handled where both engines have a time-odds  handicap.   If
              mode=1,  the  engine that gets the most time will always get the nominal time, as specified by the
              time-control options, and its opponent's time is renormalized accordingly.  If mode=0,  both  play
              with reduced time. Default: 0.

       -hideThinkingFromHumantrue/false
              Controls  the  Hide Thinking option. See OptionsMenu. Default: true.  (Replaces the Show-Thinking
              option of older xboard versions.)

       -thinking/-xthinkingor-showThinkingtrue/false
              Forces the engine to send thinking output to xboard.  Used to  be  the  only  way  to  control  if
              thinking  output  was displayed in older xboard versions, but as the thinking output in xboard 4.3
              is also used for several other purposes (adjudication, storing in PGN file) the display of  it  is
              now  controlled by the new option Hide Thinking. See OptionsMenu. Default: false.  (But if xboard
              needs the thinking output for some purpose, it makes the engine send it  despite  the  setting  of
              this option.)

       -ponder/-xponderor-ponderNextMovetrue/false
              Sets the Ponder Next Move menu option. See OptionsMenu. Default: true.

       -smpCoresnumber
              Specifies the maximum number of CPUs an SMP engine is allowed to use.  Only works for engines that
              support the XBoard/WinBoard-protocol cores feature.

       -mgor-matchGamesn
              Automatically  runs  an  n-game  match between two chess engines, with alternating colors.  If the
              `loadGameFile' or `loadPositionFile' option is set, XBoard starts each game with the given opening
              moves or the given position; otherwise, the games start with the standard initial chess  position.
              If  the  `saveGameFile'  option  is  set, a move record for the match is appended to the specified
              file. If the `savePositionFile' option is set, the final position reached  in  each  game  of  the
              match  is  appended to the specified file. When the match is over, XBoard displays the match score
              and exits. Default: 0 (do not run a match).

       -mm/-xmmor-matchModetrue/false
              Setting `matchMode' to true is equivalent to setting `matchGames' to 1.

       -sameColorGamesn
              Automatically runs an  n-game  match  between  two  chess  engines,  without  alternating  colors.
              Otherwise the same applies as for the `-matchGames' option, over which it takes precedence if both
              are specified. (See there.)  Default: 0 (do not run a match).

       -epd   This  option puts XBoard in a special mode for solving EPD test-suites, for the entire duration of
              the session.  In this mode games are aborted after a single move, and that move will  be  compared
              with  the  best-move  or  avoid-move  from  the EPD position description from which the 'game' was
              started.  Playing a best move counts as a win, playing an avoid move as a loss,  and  playing  any
              other  move  counts  as a draw.  This option should be used in combination with match mode, and an
              EPD file of starting positions with an auto-incrementing index.  Color  assignment  will  be  such
              that  the first engine plays all moves, and the second engine will be never involved.  The results
              for individual positions, as well as the time used for solving them, will be reported in the lower
              pane of the Engine Output window.

       -fcpor-firstChessProgramprogram-scpor-secondChessProgramprogram
              Name of first and second chess engine, respectively.  A second chess engine is started only in Two
              Machines (match) mode, or in Analyze mode with two engines.  The second engine is by  default  the
              same as the first.  Default for the first engine: `fairymax'.

       -feor-firstEnginenickname-seor-secondEnginenickname
              This  is an alternative to the `fcp' and `scp' options for specifying the first and second engine,
              for engines that were already registered (using the `Load Engine'  dialog)  in  XBoard's  settings
              file.  It will not only retrieve the real name of the engine, but also all options configured with
              it.  (E.g. if it is UCI, whether it should use book.)

       -fb/-xfbor-firstPlaysBlacktrue/false
              In  games  between  two  chess engines, firstChessProgram normally plays white.  If this option is
              true, firstChessProgram plays black.  In a multi-game match, this option affects the  colors  only
              for the first game; they still alternate in subsequent games.

       -fhor-firstHosthost-shor-secondHosthost
              Hosts  on  which the chess engines are to run. The default for each is `localhost'. If you specify
              another host, XBoard uses `rsh' to run the chess engine there. (You  can  substitute  a  different
              remote shell program for rsh using the `remoteShell' option described below.)

       -fdor-firstDirectorydir-sdor-secondDirectorydir
              Working  directories  in which the chess engines are to be run.  The default is "", which means to
              run the chess engine  in  the  same  working  directory  as  XBoard  itself.   (See  the  CHESSDIR
              environment  variable.)   This  option is effective only when the chess engine is being run on the
              local host; it does not work if the engine is run remotely using the -fh or -sh option.

       -initStringstringor-firstInitString-secondInitStringstring
              The string that is sent to initialize each chess engine for a new game.  Default:

                  new
                  random

              Setting this option from the command line is  tricky,  because  you  must  type  in  real  newline
              characters,  including  one  at  the  very  end.  In most shells you can do this by entering a `\'
              character followed by a newline.  Using the character sequence `\n' in the string should work too,
              though.

              If you change this option, don't remove the `new' command; it is required by all chess engines  to
              start a new game.

              You  can remove the `random' command if you like; including it causes GNU Chess 4 to randomize its
              move selection slightly so that it doesn't play the  same  moves  in  every  game.   Even  without
              `random',  GNU  Chess  4  randomizes  its choice of moves from its opening book.  Many other chess
              engines ignore this command entirely and always (or never) randomize.

              You can also try adding other commands to the initString;  see  the  documentation  of  the  chess
              engine you are using for details.

       -firstComputerStringstring-secondComputerStringstring
              The string that is sent to the chess engine if its opponent is another computer chess engine.  The
              default  is  `computer\n'.   Probably  the only useful alternative is the empty string (`'), which
              keeps the engine from knowing that it is playing another computer.

       -reuse/-xreuseor-reuseFirsttrue/false-reuse2/-xreuse2or-reuseSecondtrue/false
              If the option is false, XBoard kills off the chess engine after every game and starts it again for
              the next game.  If the option is true (the default), XBoard starts the chess engine only once  and
              uses  it  repeatedly  to  play  multiple games.  Some old chess engines may not work properly when
              reuse is turned on, but otherwise games will start faster if it is left on.

       -firstProtocolVersionversion-number-secondProtocolVersionversion-number
              This option specifies which version of  the  chess  engine  communication  protocol  to  use.   By
              default,  version-number  is  2.   In version 1, the "protover" command is not sent to the engine;
              since version 1 is a subset of version 2, nothing else changes.  Other values  for  version-number
              are not supported.

       -firstScoreAbstrue/false-secondScoreAbstrue/false
              If  this  option  is  set, the score reported by the engine is taken to be that in favor of white,
              even when the engine plays black.  Important when XBoard uses the score for adjudications,  or  in
              PGN reporting.

       -niceEnginespriority
              This  option  allows  you  to  lower  the  priority of the engine processes, so that the generally
              insatiable hunger for CPU time of chess engines does not interfere so much with  smooth  operation
              of XBoard (or the rest of your system).  Negative values could increase the engine priority, which
              is not recommended.

       -firstOptionsstring-secondOptionsstring
              The given string is a comma-separated list of (option name=option value) pairs, like the following
              example:  "style=Karpov,blunder  rate=0".  If an option announced by the engine at startup through
              the feature commands of the XBoard/WinBoard protocol matches one of the option names (i.e. "style"
              or "blunder rate"), it  would  be  set  to  the  given  value  (i.e.  "Karpov"  or  0)  through  a
              corresponding  option  command  to  the engine.  This provided that the type of the value (text or
              numeric) matches as well.

       -firstNeedsNoncompliantFENstring-secondNeedsNoncompliantFENstring
              The castling rights and e.p. fields of the FEN sent to the  mentioned  engine  with  the  setboard
              command will be replaced by the given string. This can for instance be used to run engines that do
              not understand Chess960 FENs in variant fischerandom, to make them at least understand the opening
              position,  through  setting  the  string to "KQkq -". (Note you also have to give the e.p. field!)
              Other possible applications are to provide work-arounds for engines that want to see castling  and
              e.p.  fields in variants that do not have castling or e.p.  (shatranj, courier, xiangqi, shogi) so
              that XBoard would normally omit them (string = "- -"), or to add variant-specific fields that  are
              not yet supported by XBoard (e.g. to indicate the number of checks in 3check).

       -shuffleOpenings
              Forces  shuffling  of  the  opening setup in variants that normally have a fixed initial position.
              Shufflings are symmetric for black and white, and exempt King and Rooks in  variants  with  normal
              castling.  Remains in force until a new variant is selected.

       -fischerCastling
              Specifies  Fischer castling (as in Chess960) should be enabled in variants that normally would not
              have it.  Remains in force until a new variant is selected.

   UCI+WBEngineSettings-fUCIor-firstIsUCItrue/false-sUCIor-secondIsUCItrue/false
              Indicates if the mentioned engine executable file is a UCI engine, and should be run with the  aid
              of  the  Polyglot  adapter  rather than directly.  Xboard will then pass the other UCI options and
              engine name to Polyglot on its command line, according to the option `adapterCommand'.

       -fUCCI-sUCCI-fUSI-sUSI  Options similar to `fUCI' and `sUCI', except that they use the indicated engine with the  protocol
              adapter  specified  in the `uxiAdapter' option.  This can then be configured for running a UCCI or
              USI adapter, as the need arises.

       -adapterCommandstring
              The string contains the command that should be issued  by  XBoard  to  start  an  engine  that  is
              accompanied  by  the  `fUCI' option.  Any identifier following a percent sign in the command (e.g.
              %fcp) will be considered the name of an XBoard option, and be replaced by the value of that option
              at the time the engine is started.  For starting the second engine, any leading "f" or "first"  in
              the  option  name  will  first be replaced by "s" or "second", before finding its value.  Default:
              'polyglot -noini -ec "%fcp" -ed "%fd"'

       -uxiAdapterstring
              Similar to `adapterCommand', but used for engines accompanied by the `fUCCI' or `fUSI' option,  so
              you  can  configure  XBoard  to  be  ready to handle more than one flavor of non-native protocols.
              Default: ""

       -polyglotDirfilename
              Gives the name of the directory in which the Polyglot adapter for UCI engines  resides.   Default:
              "".

       -usePolyglotBooktrue/false
              Specifies if the Polyglot book should be used as GUI book.

       -polyglotBookfilename
              Gives  the  filename of the opening book.  The book is only used when the `usePolyglotBook' option
              is set to true, and the option  `firstHasOwnBookUCI'  or  `secondHasOwnBookUCI'  applying  to  the
              engine  is set to false.  The engine will be kept in force mode as long as the current position is
              in book, and XBoard will select the book moves for it. Default: "".

       -fNoOwnBookUCIor-firstXBookor-firstHasOwnBookUCItrue/false-sNoOwnBookUCIor-secondXBookor-secondHasOwnBookUCItrue/false
              Indicates if the mentioned engine has its own opening book it should play from, rather than  using
              the external book through XBoard.  Default: depends on setting of the option `discourageOwnBooks'.

       -discourageOwnBookstrue/false
              When set, newly loaded engines will be assumed to use the GUI book, unless they explicitly specify
              differently.   Otherwise  they  will  be  assumed  to  not  use  the  GUI book, unless the specify
              differently (e.g. with `firstXBook').  Default: false.

       -bookDepthn
              Limits the use of the GUI book to the first n moves of each side.  Default: 12.

       -bookVariationn
              A value n from 0 to 100 tunes the choice of moves from the GUI books from totally random to  best-
              only. Default: 50

       -mcBookMode
              When this volatile option is specified, the probing algorithm of the GUI book is altered to always
              select  the  move  that  is  most  under-represented based on its performance.  When all moves are
              played in approximately the right proportion, a book miss will be reported,  to  give  the  engine
              opportunity  to  explore  a new move.  In addition score of the moves will be kept track of during
              the session in a book buffer.  By playing an match in  this  mode,  a  book  will  be  built  from
              scratch.   The  only  output  are the saved games, which can be converted to an actual book later,
              with the `Save Games as Book' command.  The latter command can also be used to pre-fill  the  book
              buffer before adding new games based on the probing algorithm.

       -fnstringor-firstPgnNamestring-snstringor-secondPgnNamestring
              Indicates  the  name  that  should  be  used  for  the  engine in PGN tags of engine-engine games.
              Intended to allow you to install versions of the same engine with different  settings,  and  still
              distinguish them.  Default: "".

       -defaultHashSizen
              Sets  the  size of the hash table to n MegaBytes. Together with the EGTB cache size this number is
              also used to calculate the memory setting of XBoard/WinBoard engines, for those that  support  the
              memory feature of the XBoard/WinBoard protocol. Default: 64.

       -defaultCacheSizeEGTBn
              Sets  the  size of the EGTB cache to n MegaBytes. Together with the hash-table size this number is
              also used to calculate the memory setting of XBoard/WinBoard engines, for those that  support  the
              memory feature of the XBoard/WinBoard protocol. Default: 4.

       -defaultPathEGTBfilename
              Gives  the  name  of  the  directory where the end-game tablebases are installed, for UCI engines.
              Default: "/usr/local/share/egtb".

       -egtFormatsstring
              Specifies which end-game tables are installed on the computer,  and  where.   The  argument  is  a
              comma-separated  list  of format specifications, each specification consisting of a format name, a
              colon, and a directory path name, e.g. "nalimov:/usr/local/share/egtb".  If the name part  matches
              that  of  a  format that the engine requests through a feature command, xboard will relay the path
              name for this format to the engine through an egtpath  command.   One  egtpath  command  for  each
              matching  format will be sent.  Popular formats are "nalimov" and "gaviota" DTM tablebases, syzygy
              DTZ tablebases and "scorpio" bitbases.  Default: "".

       -firstChessProgramNames={names}
              This option lets you customize the listbox with chess-engine  names  that  appears  in  the  `Load
              Engine' and `Tournament Options' dialog.  It consists of a list of strings, one per line.  When an
              engine  is loaded, the corresponding line is prefixed with "-fcp ", and processed like it appeared
              on the command line.  That means that apart from the engine command, it can contain any number  of
              XBoard  options  you  want  to  use  with  this  engine.   (Commonly  used  options  here are -fd,
              -firstXBook, -fUCI, -variant.)

              The value of this option is gradually built as you load new engines through the `Load Engine' menu
              dialog, with `Add to list' ticked.  To change it in other ways, (e.g. deleting engines),  use  the
              menu item `Edit Engine List' in the `Engine' menu.

   Tournamentoptions-defaultMatchGamesn
              Sets  the  number of games that will be used for a match between two engines started from the menu
              to n. Also used as games per pairing in other tournament formats.  Default: 10.

       -matchPausen
              Specifies the duration of the pause between two games of a match or tournament between engines  as
              n milliseconds.  Especially engines that do not support ping need this option, to prevent that the
              move they are thinking on when an opponent unexpectedly resigns will be counted for the next game,
              (leading to illegal moves there).  Default: 10000.

       -tffilenameor-tourneyFilefilename
              Specifies the name of the tournament file used in match mode to conduct a multi-player tournament.
              This  file  is  a special settings file, which stores the description of the tournament (including
              progress info), through normal options (e.g. for time control, load and save files),  and  through
              some special-purpose options listed below.

       -ttnumberor-tourneyTypenumber
              Specifies the type of tourney: 0 = round-robin, N>0 = (multi-)gauntlet with N gauntlet engines, -1
              = Swiss through external pairing engine.  Volatile option, but stored in tourney file.

       -cynumberor-tourneyCyclesnumber
              Specifies the number of cycles in a tourney.  Volatile option, but stored in tourney file.

       -participantslist
              The   list   is   a   multi-line   text   string   that   specifies   engines   occurring  in  the
              `firstChesProgramNames' list  in  the  settings  file  by  their  (implied  or  explicitly  given)
              nicknames, one engine per line.  The mentioned engines will play in the tourney.  Volatile option,
              but stored in tourney file.

       -resultsstring
              The  string  of +=- characters lists the result of all played games in a tourney.  Games currently
              playing are listed as *, while a space indicates a game that is not yet played.  Volatile  option,
              but stored in tourney file.

       -defaultTourneyNamestring
              Specifies the name of the tournament file XBoard should propose when the `Match Options' dialog is
              opened.   Any %y, %M, %d, %h, %m, %s in the string are replaced by the current year, month, day of
              the month, hours, minutes, seconds of the current time, respectively, as two-digit number.   A  %Y
              would be replaced by the year as 4-digit number. Default: empty string.

       -pairingEnginefilename
              Specifies  the  external  program  to  be used to pair the participants in Swiss tourneys.  XBoard
              communicates with this engine in the same way as it communicates with  Chess  engines.   The  only
              commands  sent  to  the  pairing  engine  are  “results  N  string”,  (where  N  is  the number of
              participants, and string the results so far in the format of the results option), and “pairing N”,
              (where N is the number of the tourney game).  To the latter the pairing engine should answer  with
              “A-B”, where A and B are participant numbers (in the range 1-N).  (There should be no reply to the
              results command.) Default: empty string.

       -afterGamestring-afterTourneystring
              When  non-empty, the given string will be executed as a system command after each tournament game,
              or after the tourney completes, respectively.  This can be used, for example, to autmatically  run
              a  cross-table  generator  on the PGN file where games are saved, to update the tourney standings.
              Default: ""

       -syncAfterRoundtrue/false-syncAfterCycletrue/false
              Controls whether different instances of XBoard concurrently running the same tournament will  wait
              for each other.  Defaults: sync after cycle, but not after round.

       -seedBasenumber
              Used  to store the seed of the pseudo-random-number generator in the tourneyFile, so that separate
              instances of XBoard working on the same tourney can take  coherent  'random'  decisions,  such  as
              picking an opening for a given game number.

   ICSoptions-ics/-xicsor-internetChessServerModetrue/false
              Connect  with  an  Internet Chess Server to play chess against its other users, observe games they
              are playing, or review games that have recently finished. Default: false.

       -icshostor-internetChessServerHosthost
              The Internet host name or address of the chess server to connect to when  in  ICS  mode.  Default:
              `chessclub.com'.   Another  popular  chess server to try is `freechess.org'.  If your site doesn't
              have a working Internet name server, try specifying the host address in  numeric  form.   You  may
              also  need  to  specify  the  numeric  address  when  using the icshelper option with timestamp or
              timeseal (see below).

       -icsportor-internetChessServerPortport-number
              The port number to use when connecting to a chess server in ICS mode. Default: 5000.

       -icshelperor-internetChessServerHelperprog-name
              An external helper program used to communicate with  the  chess  server.   You  would  set  it  to
              "timestamp"  for  ICC  (chessclub.com) or "timeseal" for FICS (freechess.org), after obtaining the
              correct version of timestamp or timeseal for your computer.  See "help timestamp" on ICC and "help
              timeseal" on FICS.  This option is shorthand for `-useTelnet -telnetProgram program'.

       -telnet/-xtelnetor-useTelnettrue/false
              This option is poorly named; it should be called useHelper.  If set to true, it  instructs  XBoard
              to  run  an external program to communicate with the Internet Chess Server.  The program to use is
              given by the telnetProgram option.  If the option is false  (the  default),  XBoard  opens  a  TCP
              socket  and  uses  its  own internal implementation of the telnet protocol to communicate with the
              ICS. See Firewalls.

       -telnetProgramprog-name
              This option is poorly named; it should be called helperProgram.  It gives the name of  the  telnet
              program  to  be  used  with  the  `gateway' and `useTelnet' options.  The default is `telnet'. The
              telnet program is invoked with the value of `internetChessServerHost' as its  first  argument  and
              the value of `internetChessServerPort' as its second argument.  See Firewalls.

       -gatewayhost-name
              If  this option is set to a host name, XBoard communicates with the Internet Chess Server by using
              `rsh' to  run  the  `telnetProgram'  on  the  given  host,  instead  of  using  its  own  internal
              implementation  of  the  telnet  protocol. You can substitute a different remote shell program for
              `rsh' using the `remoteShell' option described below.  See Firewalls.

       -internetChessServerCommPortor-icscommdev-name
              If this option is set, XBoard communicates with the ICS through the  given  character  I/O  device
              instead  of  opening  a  TCP connection.  Use this option if your system does not have any kind of
              Internet connection itself (not even a SLIP or PPP connection), but you do have dial-up access (or
              a hardwired terminal line) to an Internet service provider from which you can telnet to the ICS.

              The support for this option in XBoard is minimal. You need to set all communication parameters and
              tty modes before you enter XBoard.

              Use a script something like this:

                  stty raw -echo 9600 > /dev/tty00
                  xboard -ics -icscomm /dev/tty00

              Here replace `/dev/tty00' with the name of the device that your modem is connected to.  You  might
              have to add several more options to these stty commands. See the man pages for `stty' and `tty' if
              you  run into problems. Also, on many systems stty works on its standard input instead of standard
              output, so you have to use `<' instead of `>'.

              If you are using linux, try starting with the script below.   Change  it  as  necessary  for  your
              installation.

                  #!/bin/sh -f
                  # configure modem and fire up XBoard

                  # configure modem
                  (
                    stty 2400 ; stty raw ; stty hupcl ; stty -clocal
                    stty ignbrk ; stty ignpar ; stty ixon ; stty ixoff
                    stty -iexten ; stty -echo
                  ) < /dev/modem
                  xboard -ics -icscomm /dev/modem

              After  you  start  XBoard  in  this  way, type whatever commands are necessary to dial out to your
              Internet provider and log in.  Then telnet to ICS, using  a  command  like  `telnet  chessclub.com
              5000'.  Important: See the paragraph below about extra echoes, in Limitations.

       -icslogonor-internetChessServerLogonScriptfile-name
              Whenever  XBoard  connects to the Internet Chess Server, if it finds a file with the name given in
              this option, it feeds the file's contents to the  ICS  as  commands.  The  default  file  name  is
              `.icsrc'.  Usually the first two lines of the file should be your ICS user name and password.  The
              file  can be either in $CHESSDIR, in XBoard's working directory if CHESSDIR is not set, or in your
              home directory.

       -msLoginDelaydelay
              If you experience trouble logging on to an ICS when using the `-icslogon' option,  inserting  some
              delay  between  characters  of the logon script may help. This option adds `delay' milliseconds of
              delay between characters. Good values to try are 100 and 250.

       -icsinput/-xicsinputor-internetChessServerInputBoxtrue/false
              Sets the ICS Input Box menu option. See ModeMenu. Default: false.

       -autocomm/-xautocommor-autoCommenttrue/false
              Sets the Auto Comment menu option. See OptionsMenu. Default: false.

       -autoflag/-xautoflagor-autoCallFlagtrue/false
              Sets the Auto Flag menu option.  See OptionsMenu. Default: false.

       -autobs/-xautobsor-autoObservetrue/false
              Sets the Auto Observe menu option.  See OptionsMenu. Default: false.

       -autoKibitz
              Enables kibitzing of the engines last thinking output (depth, score, time, speed,  PV)  before  it
              moved  to the ICS, in zippy mode. The option `showThinking' must be switched on for this option to
              work.  Also diverts similar kibitz information of an opponent engine that is playing  you  through
              the ICS to the engine-output window, as if the engine was playing locally.

       -seekGraphtrue/falseor-sg
              Enables  displaying  of the seek graph by left-clicking the board when you are logged on to an ICS
              and currently idle.  The seek graph show all players currently seeking games on the  ICS,  plotted
              according  to  their  rating and the time control of the game they seek, in three different colors
              (for rated, unrated and wild games).  Computer ads are displayed as squares, human ads  are  dots.
              Default: false.

       -autoRefreshtrue/false
              Enables automatic updating of the seek graph, by having the ICS send a running update of all newly
              placed  and  removed seek ads.  This consumes a substantial amount of communication bandwidth, and
              is only supported for FICS and ICC.  Default: false.

       -backgroundObservetrue/false
              When true, boards sent to you by the ICS from other games while you are playing (e.g. because  you
              are observing them) will not be automatically displayed.  Only a summary of time left and material
              of  both  players will appear in the message field above the board.  XBoard will remember the last
              board it has received this way, and will display it instead of the position in your own game  when
              you  press  the  right mouse button.  No other information is stored on such games observed in the
              background; you cannot save such a game later,  or  step  through  its  moves.   This  feature  is
              provided  solely  for  the  benefit of bughouse players, to enable them to peek at their partner's
              game without the need to logon twice.  Default: false.

       -dualBoardtrue/false
              In combination with -backgroundObserve true, this option will display the board of the  background
              game  side  by side with that of your own game, so you can have it in view permanently.  Any board
              or holdings info coming in will be displayed on the secondary board immediately.  This feature  is
              still  experimental and largely unfinished.  There is no animation or highlighting of moves on the
              secondary board.  Default: false.

       -disguisePromotedPiecestrue/false
              When set promoted Pawns in crazyhouse/bughouse are displayed identical to primordial pieces of the
              same type, rather than distinguishable.  Default: true.

       -moves/-xmovesor-getMoveListtrue/false
              Sets the Get Move List menu option.  See OptionsMenu.  Default: true.

       -alarm/-xalarmor-icsAlarmtrue/false
              Sets the ICS Alarm menu option.  See OptionsMenu. Default: true.

       -icsAlarmTimems
              Sets the time in milliseconds for the ICS Alarm menu option.  See OptionsMenu. Default: 5000.

       lowTimeWarningtrue/false
              Controls a color change of the board as a warning your time is running  out.   See  OptionsMenu.
              Default: false.

       -pre/-xpre or -premovetrue/false
              Sets the Premove menu option. See OptionsMenu. Default: true.

       -prewhite/-xprewhiteor-premoveWhite-preblack/-xpreblackor-premoveBlack-premoveWhiteTextstring-premoveBlackTextstring
              Set  the menu options for specifying the first move for either color.  See OptionsMenu. Defaults:
              false and empty strings, so no pre-moves.

       -quiet/-xquietor-quietPlaytrue/false
              Sets the Quiet Play menu option.  See OptionsMenu.  Default: false.

       -colorizeMessagesor-colorize/-xcolorize
              Setting colorizeMessages to true tells XBoard to colorize the  messages  received  from  the  ICS.
              Colorization works only if your xterm supports ISO 6429 escape sequences for changing text colors.
              Default: true.

       -colorShoutforeground,background,bold-colorSShoutforeground,background,bold-colorCShoutforeground,background,bold-colorChannel1foreground,background,bold-colorChannelforeground,background,bold-colorKibitzforeground,background,bold-colorTellforeground,background,bold-colorChallegeforeground,background,bold-colorRequestforeground,background,bold-colorSeekforeground,background,bold-colorNormalforeground,background,bold
              These options set the colors used when colorizing ICS messages.  All ICS messages are grouped into
              one of these categories: shout, sshout, channel 1, other channel, kibitz, tell, challenge, request
              (including abort, adjourn, draw, pause, and takeback), or normal (all other messages).

              Each  foreground  or  background  argument can be one of the following: black, red, green, yellow,
              blue, magenta, cyan, white,  or  default.   Here  ``default''  means  the  default  foreground  or
              background  color  of  your  xterm.  Bold can be 1 or 0.  If background is omitted, ``default'' is
              assumed; if bold is omitted, 0 is assumed.

       -soundProgramprogname
              If this option is set to a sound-playing program that is installed and  working  on  your  system,
              XBoard  can play sound files when certain events occur, listed below.  The default program name is
              "play".  If any of the sound options is set to "$", the event rings the terminal bell by sending a
              ^G character to standard output, instead of playing a sound file.  If an  option  is  set  to  the
              empty string "", no sound is played for that event.

       -soundDirectorydirectoryname
              This  option  specifies  where  XBoard  will  look for sound files, when these are not given as an
              absolute path name.

       -soundShoutfilename-soundSShoutfilename-soundCShoutfilename-soundChannelfilename-soundChannel1filename-soundKibitzfilename-soundTellfilename-soundChallengefilename-soundRequestfilename-soundSeekfilename
              These sounds are triggered in the same way as the colorization events described above.   They  all
              default  to  "",  no  sound.   They  are  played  only  if  the colorizeMessages is on.  CShout is
              synonymous with SShout.

       -soundMovefilename
              This sound is played when a player other than yourself makes a move.  Default: "$".

       -soundRoarfilename
              This sound is played when a Lion makes a hit-and-run or double capture/ Default: "" (no sound).

       -soundIcsAlarmfilename
              This sound is used by the ICS Alarm menu option.  Default: "$".

       -soundIcsWinfilename
              This sound is played when you win an ICS game.  Default: "" (no sound).

       -soundIcsLossfilename
              This sound is played when you lose an ICS game.  Default: "" (no sound).

       -soundIcsDrawfilename
              This sound is played when you draw an ICS game.  Default: "" (no sound).

       -soundIcsUnfinishedfilename
              This sound is played when an ICS game that you are participating  in  is  aborted,  adjourned,  or
              otherwise ends inconclusively.  Default: "" (no sound).

   LoadandSaveoptions-lgfor-loadGameFilefile-lgior-loadGameIndexindex
              If  the  `loadGameFile'  option  is set, XBoard loads the specified game file at startup. The file
              name `-' specifies the standard input. If there is more than one game in the file, XBoard pops  up
              a  menu of the available games, with entries based on their PGN (Portable Game Notation) tags.  If
              the `loadGameIndex' option is set to `N', the menu is suppressed and the N th game  found  in  the
              file  is loaded immediately.  The menu is also suppressed if `matchMode' is enabled or if the game
              file is a pipe; in these cases the first  game  in  the  file  is  loaded  immediately.   Use  the
              `pxboard' shell script provided with XBoard if you want to pipe in files containing multiple games
              and  still see the menu.  If the loadGameIndex specifies an index -1, this triggers auto-increment
              of the index in `matchMode', which means that after every game the index is  incremented  by  one,
              causing  each game of the match to be played from the next game in the file. Similarly, specifying
              an index value of -2 causes the index to be incremented every two games, so that each game in  the
              file  is used twice (with reversed colors).  The `rewindIndex' option causes the index to be reset
              to the first game of the file when it has reached a specified value.

       -rewindIndexn
              Causes a position file or game file to be rewound to its beginning after n positions or  games  in
              auto-increment `matchMode'.  See `loadPositionIndex' and `loadGameIndex'.  default: 0 (no rewind).

       -tdor-timeDelayseconds
              Time  delay  between  moves during `Load Game' or `Analyze File'.  Fractional seconds are allowed;
              try `-td 0.4'.   A  time  delay  value  of  -1  tells  XBoard  not  to  step  through  game  files
              automatically. Default: 1 second.

       -sgfor-saveGameFilefile
              If  this  option  is  set, XBoard appends a record of every game played to the specified file. The
              file name `-' specifies the standard output.

       -autosave/-xautosaveor-autoSaveGamestrue/false
              Sets the Auto Save menu option.  See OptionsMenu.  Default: false.  Ignored if `saveGameFile'  is
              set.

       -onlyOwnGamestrue/false
              Suppresses auto-saving of ICS observed games. Default: false.

       -lpfor-loadPositionFilefile-lpior-loadPositionIndexindex
              If  the `loadPositionFile' option is set, XBoard loads the specified position file at startup. The
              file name `-' specifies the standard input. If the `loadPositionIndex' option is set to N, the Nth
              position found  in  the  file  is  loaded;  otherwise  the  first  position  is  loaded.   If  the
              loadPositionIndex specifies an index -1, this triggers auto-increment of the index in `matchMode',
              which  means that after every game the index is incremented by one, causing each game of the match
              to be played from the next position in the file. Similarly, specifying an index value of -2 causes
              the index to be incremented every two games, so that each position in the file is used twice (with
              the engines playing opposite colors).  The `rewindIndex' option causes the index to  be  reset  to
              the first position of the file when it has reached a specified value.

       -spfor-savePositionFilefile
              If  this  option  is  set,  XBoard  appends the final position reached in every game played to the
              specified file. The file name `-' specifies the standard output.

       -positionDirdirectory
              Specifies the directory where file browsing should start when using the `Load Position' menu item.

       -pgnExtendedInfotrue/false
              If this option is set, XBoard saves depth, score and time used for each move that the engine found
              as a comment in the PGN file.  Default: false.

       -pgnTimeLefttrue/false
              If this option is set, XBoard will save the remaining clock time for  the  player  that  has  just
              moved  as part of the `pgnExtendedInfo', rather than the time that player thought about his latest
              move.  Default: false.

       -pgnEventHeaderstring
              Default: false.  Sets the name used in the PGN event tag  to  string.   Default:  "Computer  Chess
              Game".

       -pgnNumberTagtrue/false
              Include  the  (unique)  sequence number of a tournament game into the saved PGN file as a 'number'
              tag.  Default: false.

       -saveOutOfBookInfotrue/false
              Include the information on how the engine(s) game out of its opening book in a special 'annotator'
              tag with the PGN file.  Default: true.

       -oldsave/-xoldsaveor-oldSaveStyletrue/false
              Sets the Old Save Style menu option.  See OptionsMenu.  Default: false.

       -gameListTagsstring
              The character string lists the PGN tags that should be printed in the Game List, and their  order.
              The  meaning  of  the codes is e=event, s=site, d=date, o=round, p=players, r=result, w=white Elo,
              b=black Elo, t=time control, v=variant, a=out-of-book info, c=result comment.  Default: "eprd"

       -inior-settingsFilefilename-saveSettingsFilefilename@filename
              When XBoard encounters an option -settingsFile (or -ini for short), or @filename, it tries to read
              the mentioned file, and substitutes the contents of it (presumaby more  command-line  options)  in
              place  of  the  option.   In  the  case  of -ini or -settingsFile, the name of a successfully read
              settings file is also remembered as the file to use for saving settings (automatically on exit, or
              on user command).   An  option  of  the  form  @filename  does  not  affect  saving.   The  option
              -saveSettingsFile  does  specify a name of the file to use for saving, without reading any options
              from it, and is thus also effective when the file did not exist yet.   So  the  settings  will  be
              saved  to  the  file  specified  in  the  last -saveSettingsFile or succesful -settingsFile / -ini
              command, if any, and in /etc/xboard/xboard.conf otherwise.  Usualy the latter is  only  accessible
              for  the  system  administrator, though, and will be used to contain system-wide default settings,
              amongst which a -saveSettingsFile and -settingsFile options to specify a settings file  accessible
              to the individual user, such as ~/.xboardrc in the user's home directory.

       -saveSettingsOnExittrue/false
              Controls saving of options on the settings file.  See OptionsMenu.  Default: true.

   Userinterfaceoptions-noGUI Suppresses  all  GUI  functions  of  XBoard (to speed up automated ultra-fast engine-engine games,
              which you don't want to watch).  There will be no board or clock updates, no  printing  of  moves,
              and no update of the icon on the task bar in this mode.

       -logoSizeN
              This  option controls the drawing of player logos next to the clocks.  The integer N specifies the
              width of the logo in pixels; the logo height will always be half the width.  When N = 0, no  logos
              will be diplayed.  Default: 0.

       -firstLogoimagefile-secondLogoimagefile
              Specify  the  images to be used as player logos when `logoSize' is non-zero, next to the white and
              black clocks, respectively.

       -autoLogotrue/false-logoDirfilename
              When `autoLogo' is set, XBoard will search for a PNG image file with the name of the engine or ICS
              in the  directory  specified  by  `logoDir'.   For  a  human  player  it  will  look  for  a  file
              <username>.png in this directory, but only when ~/.logo.png does not provide one.

       -recentEnginesnumber-recentEngineListlist
              When the number is larger than zero, it determines how many recently used engines will be appended
              at  the  bottom  of  the  `Engines'  menu.  The engines will be saved in your settings file as the
              option `recentEngineList', by their nicknames, and the most  recently  used  one  will  always  be
              sorted  to  the  top.  If the list after that is longer than the specified number, the last one is
              discarded.  Changes in the list will only become visible the next session, provided you saved  the
              settings.  Default: 6.

       -oneClickMovetrue/false
              When set, this option allows you to enter moves by only clicking the to- or from-square, when only
              a  single  legal move to or from that square is possible.  Double-clicking a piece (or clicking an
              already selected piece) will instruct that piece to make the  only  capture  it  can  legally  do.
              Default: false.

       -monoMousetrue/false
              When  set  button  1 clicks on empty squares in Edit Position mode will be interpreted as button 3
              clicks, so they place a piece.  Default: false.

       -movesound/-xmovesoundor-ringBellAfterMovestrue/false
              Sets the Move Sound menu option.  See OptionsMenu.  Default: false.  For compatibility  with  old
              XBoard versions, -bell/-xbell are also accepted as abbreviations for this option.

       -analysisBellN
              When N is non-zero, the Move Sound will be played whenever a new PV arrives in analysis mode after
              more than N seconds of analysis.  Default: 0.

       -exit/-xexitor-popupExitMessagetrue/false
              Sets the Popup Exit Message menu option.  See OptionsMenu. Default: true.

       -popup/-xpopupor-popupMoveErrorstrue/false
              Sets the Popup Move Errors menu option.  See OptionsMenu. Default: false.

       -queen/-xqueenor-alwaysPromoteToQueentrue/false
              Sets the Always Queen menu option.  See OptionsMenu.  Default: false.

       -sweepPromotionstrue/false
              Sets the `Almost Always Promote to Queen' menu option.  See OptionsMenu.  Default: false.

       -legal/-xlegalor-testLegalitytrue/false
              Sets the Test Legality menu option.  See OptionsMenu.  Default: true.

       -sizeor-boardSize(sizeName|n1,n2,n3,n4,n5,n6,n7)
              Determines  how  large  the board will be, by selecting the pixel size of the pieces and setting a
              few related parameters.  The sizeName can  be  one  of:  Titanic,  giving  129x129  pixel  pieces,
              Colossal  116x116,  Giant  108x108, Huge 95x95, Big 87x87, Large 80x80, Bulky 72x72, Medium 64x64,
              Moderate 58x58, Average 54x54, Middling 49x49, Mediocre 45x45, Small  40x40,  Slim  37x37,  Petite
              33x33,  Dinky  29x29,  Teeny  25x25,  or Tiny 21x21.  Xboard installs with a set of scalable (svg)
              piece images, which it scales to any of the requested sizes.   The  square  size  can  further  be
              continuously  scaled  by sizing the board window, but this only adapts the size of the pieces, and
              has no effect on the width of the grid lines or the font choice (both of which would depend on  he
              selected  boardSize).   The  default  depends  on the size of your screen; it is approximately the
              largest size that will fit without clipping.

              You can select other sizes or vary other layout parameters by providing a list of  comma-separated
              values  (with  no spaces) as the argument.  You do not need to provide all the values; for any you
              omit from the end of the list, defaults are taken from the nearest built-in size.  The value  `n1'
              gives  the  piece  size, `n2' the width of the black border between squares, `n3' the desired size
              for the clockFont, `n4' the desired size  for  the  coordFont,  `n5'  the  desired  size  for  the
              messageFont,  `n6'  the  smallLayout  flag  (0  or 1), and `n7' the tinyLayout flag (0 or 1).  All
              dimensions are in pixels.  If the border between squares is  eliminated  (0  width),  the  various
              highlight  options  will not work, as there is nowhere to draw the highlight.  If smallLayout is 1
              and `titleInWindow' is true, the window layout is rearranged to make more room for the title.   If
              tinyLayout  is 1, the labels on the menu bar are abbreviated to one character each and the buttons
              in the button bar are made narrower.

       -overrideLineGapn
              When n >= 0, this forces the width of the black border between squares to n pixels for  any  board
              size.  Mostly used to suppress the grid entirely by setting n = 0, e.g. in xiangqi or just getting
              a prettier picture. When n < 0 this the size-dependent width of the grid lines is  used.  Default:
              -1.

       -coords/-xcoordsor-showCoordstrue/false
              Sets  the  Show  Coords  menu  option.  See OptionsMenu.  Default: false.  The `coordFont' option
              specifies what font to use.

       -autoraise/-xautoraiseor-autoRaiseBoardtrue/false
              Sets the Auto Raise Board menu option.  See OptionsMenu.  Default: true.

       -autoflip/-xautoflipor-autoFlipViewtrue/false
              Sets the Auto Flip View menu option.  See OptionsMenu.  Default: true.

       -flip/-xflipor-flipViewtrue/false
              If Auto Flip View is not set, or if you are observing but not participating in a  game,  then  the
              positioning of the board at the start of each game depends on the flipView option.  If flipView is
              false  (the  default), the board is positioned so that the white pawns move from the bottom to the
              top; if true, the black pawns move from the bottom to the top.  In any case, the Flip menu  option
              (see OptionsMenu) can be used to flip the board after the game starts.

       -title/-xtitleor-titleInWindowtrue/false
              If  this  option  is  true,  XBoard displays player names (for ICS games) and game file names (for
              `Load Game') inside its main window. If the option is false (the  default),  this  information  is
              displayed  only  in  the  window  banner.  You  probably  won't want to set this option unless the
              information is not showing up in the banner, as happens with a few X window managers.

       -buttons/-xbuttonsor-showButtonBarTrue/False
              If this option is False, xboard omits the [<<] [<] [P]  [>]  [>>]  button  bar  from  the  window,
              allowing the message line to be wider.  You can still get the functions of these buttons using the
              menus or their keyboard shortcuts.  Default: true.

       -evalZoomfactor
              The  score  interval  (-1,1) is blown up on the vertical axis of the Evaluation Graph by the given
              factor.  Default: 1

       -evalThresholdn
              Score below n (centiPawn) are plotted as 0 in the Evaluation Graph.  Default: 25

       -mono/-xmonoor-monoModetrue/false
              Determines whether XBoard displays its pieces and squares with two colors (true) or four  (false).
              You shouldn't have to specify `monoMode'; XBoard will determine if it is necessary.

       -showTargetSquarestrue/false
              Determines whether XBoard can highlight the squares a piece has legal moves to, when you grab that
              piece with the mouse.  Default: false.

       -flashCountcount-flashRaterate-flash/-xflash
              These  options enable flashing of pieces when they land on their destination square.  `flashCount'
              tells XBoard how many  times  to  flash  a  piece  after  it  lands  on  its  destination  square.
              `flashRate'  controls  the rate of flashing (flashes/sec).  Abbreviations: `flash' sets flashCount
              to 3.  `xflash' sets flashCount to 0.  Defaults:  flashCount=0 (no flashing), flashRate=5.

       -highlight/-xhighlightor-highlightLastMovetrue/false
              Sets the Highlight Last Move menu option. See OptionsMenu. Default: false.

       -highlightMoveWithArrowtrue/false
              Sets the Highlight with Arrow menu option. See OptionsMenu. Default: false.

       -blind/-xblindor-blindfoldtrue/false
              Sets the Blindfold menu option.  See OptionsMenu.  Default: false.

       -periodic/-xperiodicor-periodicUpdatestrue/false
              Controls updating of current move andnode counts in analysis mode. Default: true.

       -fSAN-sSAN  Causes the PV in thinking output of the mentioned engine to be  converted  to  SAN  before  it  is
              further  processed.  Warning: this might lose engine output not understood by the parser, and uses
              a lot of CPU power.  Default: the PV is displayed exactly as the engine produced it.

       -showEvalInMoveHistorytrue/false
              Controls whether the evaluation scores and search depth of engine moves  are  displayed  with  the
              move in the move-history window.  Default: true.

       -clockFontfont
              The  font  used  for  the  clocks. If the option value is a pattern that does not specify the font
              size, XBoard tries to choose an appropriate font for the board  size  being  used.   Default  Xaw:
              -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*.  Default GTK: Sans Bold %d.

       -coordFontfont
              The  font used for rank and file coordinate labels if `showCoords' is true. If the option value is
              a pattern that does not specify the font size, XBoard tries to choose an appropriate font for  the
              board  size  being  used.  Default Xaw: -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*.  Default GTK:
              Sans Bold %d.

       -messageFontfont
              The font used for popup dialogs, menus, etc.  If the option value  is  a  pattern  that  does  not
              specify  the  font size, XBoard tries to choose an appropriate font for the board size being used.
              Default Xaw: -*-helvetica-medium-r-normal--*-*-*-*-*-*-*-*.  Default GTK: Sans Bold %d

       -tagsFontfont
              The font used in the Edit Tags dialog.  If the option value contains %d, XBoard will replace it by
              an appropriate font for the board size being used.  (Only  used  in  GTK  build.)   Default:  Sans
              Normal %d.

       -commentFontfont
              The font used in the Edit Comment dialog.  If the option value contains %d, XBoard will replace it
              by  an  appropriate  font for the board size being used.  (Only used in GTK build.)  Default: Sans
              Normal %d.

       -icsFontfont
              The font used to display ICS output in the ICS  Chat window.  As ICS output often contains  tables
              aligned by spaces, a mono-space font is recommended here.  If the option value contains %d, XBoard
              will  replace  it by an appropriate font for the board size being used.  (Only used in GTK build.)
              Default: Monospace Normal %d.

       -moveHistoryFontfont
              The font used in Move History and Engine Output windows.  As these windows display  mainly  moves,
              one could use a figurine font here.  If the option value contains %d, XBoard will replace it by an
              appropriate  font  for the board size being used.  (Only used in GTK build.)  Default: Sans Normal
              %d.

       -gameListFontfont
              The font used in the listbox of the Game List window.  If the option  value  contains  %d,  XBoard
              will  replace  it by an appropriate font for the board size being used.  (Only used in GTK build.)
              Default: Sans Bold %d.

       -fontSizeTolerancetol
              In the font selection algorithm, a nonscalable font will be preferred over a scalable font if  the
              nonscalable font's size differs by `tol' pixels or less from the desired size.  A value of -1 will
              force  a  scalable  font  to always be used if available; a value of 0 will use a nonscalable font
              only if it is exactly the right size; a large value (say 1000) will force a  nonscalable  font  to
              always be used if available.  Default: 4.

       -pidor-pieceImageDirectorydir
              This  options  control what piece images xboard uses.  XBoard will look in the specified directory
              for an image in png  or  svg  format  for  every  piece  type,  with  names  like  BlackQueen.svg,
              WhiteKnight.svg  etc.   When neither of these is found (or no valid directory is specified) XBoard
              will first ty to use an image White/BlackTile.svg in that same  directory,  and  if  that  is  not
              present  either  use  the  svg  piece  that  was installed with it (from the source-tree directory
              `svg').  Both svg and png images will be scaled by XBoard to the required size, but the png pieces
              lose much in quality when scaled too much.  Default: "".

       -inscriptionsutf8string
              The positions in the utf8string correspond to XBoard's piece types, and for each type a glyph  can
              be  defined.   This glyph will then be rendered on top of the image for the piece.  This is useful
              in combination with the White/BlackTile.svg images, which could be the  image  of  a  blank  Shogi
              tile, for writing the kanji piece name on top of it on the fly.  Default: "".

       -whitePieceColorcolor-blackPieceColorcolor-lightSquareColorcolor-darkSquareColorcolor-highlightSquareColorcolor-preoveHighlightColorcolor-lowTimeWarningColorcolor
              Colors to use for the pieces, squares, and square highlights.  Defaults:

                  -whitePieceColor       #FFFFCC
                  -blackPieceColor       #202020
                  -lightSquareColor      #C8C365
                  -darkSquareColor       #77A26D
                  -highlightSquareColor  #FFFF00
                  -premoveHighlightColor #FF0000
                  -lowTimeWarningColor   #FF0000

              On a grayscale monitor you might prefer:

                  -whitePieceColor       gray100
                  -blackPieceColor       gray0
                  -lightSquareColor      gray80
                  -darkSquareColor       gray60
                  -highlightSquareColor  gray100
                  -premoveHighlightColor gray70
                  -lowTimeWarningColor   gray70

              The PieceColor options only work properly if the image files defining the pieces were pure black &
              white (possibly anti-aliased to produce gray scales and semi-transparancy), like the pieces images
              that  come with the install.  Their effect on colored pieces is undefined.  The SquareColor option
              only have an effect when no board textures are used.

       -trueColorstrue/false
              When set, this option suppresses the effect  of the PieceColor options mentioned above.   This  is
              recommended for images that are already colored.

       -useBoardTexturetrue/false-liteBackTextureFilefilename-darkBackTextureFilefilename
              Indicate  the png image files to be used for drawing the board squares, and if they should be used
              rather than using simple colors.  The algorithm for cutting squares out of a given bitmap is  such
              that  the  picture  is perfectly reproduced when a bitmap the size of the complete board is given.
              If the filename ends in "-NxM.png", with integer N and M, it is assumed to contain a bitmap  of  a
              complete  board  of  N  files  and  M ranks, and XBoard will scale it to exactly match the current
              square size.  If N=M=0 it scales the entire bitmap to the size of the board, irrespective  of  the
              number of files and ranks of the latter.  Without any -NxM suffix textures are only blown up by an
              integer factor when they are smaller than the square size, or, when the name starts with "xq", too
              small to cover the complete Xiangqi board.  Default: false and ""

       -drag/-xdragor-animateDraggingtrue/false
              Sets the Animate Dragging menu option. See OptionsMenu.  Default: true.

       -animate/-xanimateor-animateMovingtrue/false
              Sets the Animate Moving menu option. See OptionsMenu.  Default: true.

       -animateSpeedn
              Number of milliseconds delay between each animation frame when Animate Moves is on.

       -autoDisplayCommenttrue/false-autoDisplayTagstrue/false
              If  set  to  true,  these options cause the window with the move comments, and the window with PGN
              tags, respectively, to pop up automatically when such tags or comments are encountered during  the
              replaying a stored or loaded game.  Default: true.

       -pasteSelectiontrue/false
              If  this option is set to true, the Paste Position and Paste Game options paste from the currently
              selected text.  If false, they paste from the clipboard.  Default: false.

       -autoCopyPVtrue|false
              When this option is set, the position displayed  on  the  board  when  you  terminate  a  PV  walk
              (initiated  by  a  right-click  on board or engine-output window) will be automatically put on the
              clipboard as FEN.  Default: false.

       -dropMenutrue|false
              This option allows you to emulate old behavior, where the right mouse button brings  up  the  (now
              deprecated)  drop  menu rather than displaying the position at the end of the principal variation.
              Default: False.

       -pieceMenutrue|false
              This option allows you to emulate old behavior, where the right mouse button brings  up  the  (now
              deprecated)  piece  menu in Edit Position mode.  From this menu you can select the piece to put on
              the square you clicked to bring up the menu, or select items such as `clear board'.  You can  also
              `promote'  or `demote' a clicked piece to convert it into an unorthodox piece that is not directly
              in the menu, or give the move to `black' or `white'.

       -variationstrue|false
              When this option is on, you can start new variations in Edit Game or Analyze mode by  holding  the
              Shift  key  down  while entering a move.  When it is off, the Shift key will be ignored.  Default:
              False.

       -appendPVtrue|false
              When this option is on, a button 3 click left of a PV in the Engine Output window  will  play  the
              first  move  of  that  PV  in  Analyze mode, or as many moves as you walk through it by moving the
              mouse.  Default: False.

       -absoluteAnalysisScorestrue|false
              When true, scores on the Engine Output window during analysis  will  be  printed  from  the  white
              point-of-view, rather than the side-to-move point-of-view.  Default: False.

       -scoreWhitetrue|false
              When  true,  scores  will always be printed from the white point-of-view, rather than the side-to-
              move point-of-view.  Default: False.

       -memoHeaderstrue|false
              When true, column headers will be displayed in the Engine Output window for the depth, score, time
              and nodes data.  A button 3 click on these headers will hide or show the corresponding data.  (Not
              intended for dynamic use, as already printed data of the current search  will  not  be  affected!)
              Defaul: False.

   AdjudicationOptions-adjudicateLossThresholdn
              If  the given value is non-zero, XBoard adjudicates the game as a loss if both engines agree for a
              duration of 6 consecutive ply that the score is below the given score threshold for  that  engine.
              Make   sure   the   score   is   interpreted   properly  by  XBoard,  using  `-firstScoreAbs'  and
              `-secondScoreAbs' if needed.  Default: 0 (no adjudication)

       -adjudicateDrawMovesn
              If the given value is non-zero, XBoard adjudicates the game as a draw if after the given number of
              moves it was not yet decided. Default: 0 (no adjudication)

       -checkMatestrue/false
              If this option is set, XBoard detects all checkmates and stalemates, and ends the game as soon  as
              they occur.  Legality-testing must be switched on for this option to work.  Default: true

       -testClaimstrue/false
              If this option is set, XBoard verifies all result claims made by engines, and those who send false
              claims  will forfeit the game because of it.  Legality-testing must be switched on for this option
              to work. Default: true

       -materialDrawstrue/false
              If this option is set, XBoard adjudicates games as draws when there is no sufficient material left
              to inflict a checkmate.  This applies to KBKB with like bishops (any  number,  actually),  and  to
              KBK, KNK and KK.  Legality-testing must be switched on for this option to work. Default: true

       -trivialDrawstrue/false
              If  this  option  is  set,  XBoard  adjudicates  games as draws that cannot be usually won without
              opponent cooperation. This applies to KBKB with unlike bishops, and to KBKN, KNKN, KNNK, KRKR  and
              KQKQ.  The draw is called after 6 ply into these end-games, to allow quick mates that can occur in
              some exceptional positions to be found by the engines.   KQKQ  does  not  really  belong  in  this
              category,  and  might  be  taken  out  in  the  future.   (When  bitbase-based  adjudications  are
              implemented.)  Legality-testing must be on for this option to work. Default: false

       -ruleMovesn
              If the given value is non-zero, XBoard adjudicates the game as a draw after the  given  number  of
              consecutive  reversible moves. Engine draw claims are always accepted after 50 moves, irrespective
              of the given value of n.

       -repeatsToDrawn
              If the given value is non-zero, xboard adjudicates the game as a draw if a  position  is  repeated
              the  given  number  of times. Engines draw claims are always accepted after 3 repeats, (on the 3rd
              occurrence, actually), irrespective of the value of n.  Beware that positions that have  different
              castling or en-passant rights do not count as repeats, XBoard is fully e.p. and castling aware!

   Installoptions--show-configparameter
              When  called  with  this  option,  XBoard  will  close immediately after printing the value of the
              indicated configuration parameter, or, when no parameter was given, after printing a list  of  all
              such  parameters.  Currently the only valid values for parameter are Datadir and Sysconfdir.  This
              option can be used by install scripts for board themes to figure out where  the  currently  active
              XBoard stores its data.

       -datetimestamp-saveDatetimestamp
              These  options  specify an epoch as an integer number.  The `saveDate' option is written by XBoard
              in the settings file every time the settings are saved, with the current time, so that later  runs
              of  XBoard  can  know  this.  The `date' option can be included in settings files to indicate when
              lines following it were added to those files.  Some options will be ignored if the epoch specified
              by the latest `date' option predates the -saveDate setting (implying  they  must  have  been  seen
              before).

       -autoInstalllist
              When  the  list  is  set  to  a  non-empty  string, XBoard will scan the operating system's plugin
              directory for engines supporting UCI and XBoard protocol at startup.  When it finds an engine that
              was installed after it last saved its settings, a line to launch that engine (as per specs in  the
              plugin  file) is appended to the -firstChessProgramNames list of installed engines.  In the future
              it will be possible to use the autoInstall list to limit this automatic adding of engines based on
              the chess variant they play.

       -addMasterOptionstring
              Adds the mentioned string as an additional line of XBoard's master settings file, after  adding  a
              line  with  a  `date'  option to timestamp it.  Intended to add options of the 'install' type (see
              below) to the master file, which will then be processed by any XBoard that has not seen them since
              it last saved its settings.

       -autoClose
              The presence of this option cause XBoard to close immediately after  processing  all  its  options
              (from  settings file and command line).  Typically used from install scripts together with options
              that change XBoard's settings files, so  that  XBoard  can  be  run  in  batch  mode  rather  than
              interactively.

       -installEnginestring
              Adds  the  given  string as an additional line to the value of the `firstChessProgramNames' option
              when the -saveDate setting preceeds the -date setting.  Intended for adding to the master settings
              file with the aid of  -addMasterOption  in  the  install  script  of  engines,  as  a  method  for
              broadcasting  the  presence  of  a  new engine to all users, which would then see it automatically
              registered with XBoard.  Made obsolete by the advent of the plugin standard (see the `autoInstall'
              option), which broadcasts such presence in a non-XBoard-specific way by dropping *.eng files in  a
              certain system directory.

       -installThemestring
              Adds  the  given  string  as  an  additional  line to the value of the -themeNames option when the
              -saveDate setting preceeds the -date setting.  Intended for adding to  the  master  settings  file
              with  the  aid of -addMasterOption in the install script of board graphics themes, as a method for
              broadcasting the availability of a new theme to all users, who would then  see  the  theme  appear
              automatically in the listbox in the View Board menu dialog next time they run XBoard.

   Otheroptions-ncp/-xncpor-noChessProgramtrue/false
              If  this  option is true, XBoard acts as a passive chessboard; it does not start a chess engine at
              all. Turning on this option also turns off clockMode. Default: false.

       -viewer-viewerOptionsstring
              Presence of the volatile option `viewer'  on  the  command  line  will  cause  the  value  of  the
              persistent  option  `viewerOptions'  as  stored in the settings file to be appended to the command
              line.  The `view' option will be used by desktop associations with game or position file types, so
              that `viewerOptions' can be used to configure the exact mode XBoard will start in when  it  should
              act  on  such  a file (e.g. in -ncp mode, or analyzing with your favorite engine). The options are
              also automatically appended when Board is invoked with a single argument not being an option name,
              which is then assumed to be the name of a `loadGameFile'  or  (when  the  name  ends  in  .fen)  a
              `loadPositionFile'.  Default: "-ncp -engineOutputUp false -saveSettingsOnExit false".

       -tourneyOptionsstring
              When  XBoard  is invoked with a single argument that is a file with .trn extension, it will assume
              this argument to be the value of a `tourneyFile' option, and append the value  of  the  persistent
              option  `tourneyOptions'  as  stored  in the settings file to the command line.  Thus the value of
              `tourneyOptions' can be used to configure XBoard to automatically start running a tournament  when
              it should act on such a file.  Default: "-ncp -mm -saveSettingsOnExit false".

       -modeor-initialModemodename
              If  this  option is given, XBoard selects the given modename from the Mode menu after starting and
              (if  applicable)  processing  the  loadGameFile  or  loadPositionFile  option.  Default:  ""   (no
              selection).   Other  supported  values  are  MachineWhite,  MachineBlack,  TwoMachines,  Analysis,
              AnalyzeFile, EditGame, EditPosition, and Training.

       -variantvarname
              Activates  (sometimes partial) support for playing  chess  variants  against  a  local  engine  or
              editing variant games.  This flag is not needed in ICS mode.  Recognized variant names are:

                  normal        Normal chess
                  wildcastle    Shuffle chess, king can castle from d file
                  nocastle      Shuffle chess, no castling allowed
                  fischerandom  Fischer Random shuffle chess
                  bughouse      Bughouse, ICC/FICS rules
                  crazyhouse    Crazyhouse, ICC/FICS rules
                  losers        Lose all pieces or get mated (ICC wild 17)
                  suicide       Lose all pieces including king (FICS)
                  giveaway      Try to have no legal moves (ICC wild 26)
                  twokings      Weird ICC wild 9
                  kriegspiel    Opponent's pieces are invisible
                  atomic        Capturing piece explodes (ICC wild 27)
                  3check        Win by giving check 3 times (ICC wild 25)
                  shatranj      An ancient precursor of chess (ICC wild 28)
                  xiangqi       Chinese Chess (on a 9x10 board)
                  shogi         Japanese Chess (on a 9x9 board & piece drops)
                  capablanca    Capablanca Chess (10x8 board, with Archbishop
                                and Chancellor pieces)
                  gothic        similar, with a better initial position
                  caparandom    An FRC-like version of Capablanca Chess (10x8)
                  janus         A game with two Archbishops (10x8 board)
                  courier       Medieval intermediate between shatranj and
                                modern Chess (on 12x8 board)
                  falcon        Patented 10x8 variant with two Falcon pieces
                  berolina      Pawns capture straight ahead, and move diagonally
                  cylinder      Pieces wrap around the board edge
                  knightmate    King moves as Knight, and vice versa
                  super         Superchess (shuffle variant with 4 exo-pieces)
                  makruk        Thai Chess (shatranj-like, P promotes on 6th rank)
                  asean         ASEAN Chess (a modernized version of Makruk)
                  spartan       Spartan Chess (black has unorthodox pieces)
                  great         Great Shatranj, a 10x8 variant without sliders
                  grand         Grand Chess, on 10x10 with Capablanca pieces
                  lion          Mighty-Lion Chess, with a multi-capturing Lion
                  elven         Eleven Chess, with Lion and crowned sliders on 10x10
                  chu           Chu Shogi, historic 12x12 variant with 2x46 pieces
                  fairy         A catchall variant in which all piece types
                                known to XBoard can participate (8x8)
                  unknown       Catchall for other unknown variants

              In  the  shuffle  variants,  XBoard  does shuffle the pieces, although you can still do it by hand
              using Edit Position.  Some variants are supported  only  in  ICS  mode,  including  bughouse,  and
              kriegspiel.  Berolina and cylinder chess are only partially supported, and can only be played with
              legality testing off.

              Apart  from  these  standard  variants,  engines  can define variants of arbitrary names, briefing
              XBoard transparently on the rules for piece movement, board size and initial setup, so  that  they
              work  nearly  as  well as fully-supported standard variants.  (But obviously only while using that
              engine.)  The user might have to alter the adjudication settings for some variants, however.  E.g.
              it  makes  no sense to adjudicate a draw after 50 reversible moves in variants that have a 64-move
              rule, or no similar rule at all.

              Default: "normal". Except when the first engine gave an explicit list of variants it supports, and
              'normal' is not amongst those.  In that case the first variant the engine mentioned  it  did  play
              will be chosen.

       -boardHeightN
              Allows  you to set a non-standard number of board ranks in any variant.  If the height is given as
              -1, the default height for the variant is used.  Default: -1

       -boardWidthN
              Allows you to set a non-standard number of board files in any variant.  If the width is  given  as
              -1,  the  default  width for the variant is used.  With a non-standard width, the initial position
              will always be an empty board, as the usual opening array will not fit.  Default: -1

       -holdingsSizeN
              Allows you to set a non-standard size for the holdings in any variant.  If the size  is  given  as
              -1,  the  default holdings size for the variant is used.  The first N piece types will go into the
              holdings on capture, and you will be able to drop them on the board in stead of  making  a  normal
              move. If size equals 0, there will be no holdings.  Default: -1

       -defaultFrcPositionN
              Specifies  the number of the opening position in shuffle games like Chess960.  A value of -1 means
              the position is randomly generated by XBoard at the beginning of every game.  Default: -1

       -pieceToCharTablestring
              The characters that are used to represent the piece types XBoard knows in  FEN  diagrams  and  SAN
              moves.  You should not have to use this option often: each variant has its own default setting for
              the  piece  representation  in FEN, which should be sufficient in normal use.  The string argument
              has to specify an even number of pieces (or it will be ignored), as white and black pieces have to
              be given separately (in that order). The last letter for each color will be the King.  The letters
              before that will be PNBRQ and then a whole host of fairy pieces in an order  that  has  not  fully
              crystallized  yet  (currently  FEACWMOHIJGDVLSU,  F=Ferz,  Elephant,  A=Archbishop,  C=Chancellor,
              W=Wazir, M=Commoner, O=Cannon, H=Nightrider). You should list at least all pieces  that  occur  in
              the  variant  you  are playing. If you have fewer characters in the string than XBoard has pieces,
              the pieces not mentioned will get assigned a period, and will not be usable in the  variant.   You
              can  also  explicitly  assign  pieces a period, in which case they will not be counted in deciding
              which captured pieces can go into the holdings.  A tilde '~' as a piece name does mean this  piece
              is  used to represent a promoted Pawn in crazyhouse-like games, i.e. on capture it turns back to a
              Pawn.  A '+' similarly indicates the piece is a shogi-style promoted piece, that should revert  to
              its  non-promoted  version  on  capture  (rather than to a Pawn).  By default the second 11 pieces
              known to XBoard are the promoted forms of the first  11.   A  piece  specified  by  the  character
              combination  ^  plus letter will be assumed to be the promoted form of the piece indicated by that
              letter, and get a '+' assigned.  To get around the limitation of the alphabet, piece IDs can  also
              be  'dressed  letters', i.e. a single letter (upper case for white, lower case for black) followed
              by a single quote or an exclamation point.  Default: "" (meaning the default for  the  variant  is
              used).

       -pieceNickNamesstring
              The characters in the string are interpreted the same way as in the `pieceToCharTable' option. But
              on input, piece-ID letters are first looked up in the nicknames, and only if not defined there, in
              the normal pieceToCharTable. This allows you to have two letters designate the same piece, (e.g. N
              as  an  alternative to H for Horse in Xiangqi), to make reading of non-compliant notations easier.
              Default: ""

       -colorNickNamesstring
              The side-to-move field in a FEN will be first matched against the letters  in  the  string  (first
              character  for  white,  second  for black), before it is matched to the regular 'w' and 'b'.  This
              makes it easier to read non-compliant FENs, which, say, use 'r' for white.  Default: ""

       -debug/-xdebugor-debugModetrue/false
              Turns on debugging printout.

       -debugFilefilenameor-nameOfDebugFilefilename
              Sets the name of the file to which XBoard saves debug information (including all communication  to
              and  from the engines).  A `%d' in the given file name (e.g. game%d.debug) will be replaced by the
              unique sequence number of a tournament game, so that the debug output of each game will be written
              on a separate file.

       -engineDebugOutputnumber
              Specifies how XBoard should handle unsolicited output from the engine, with respect to  saving  it
              in  the debug file.  The output is further (hopefully) ignored.  If number=0, XBoard refrains from
              writing such spurious output to the debug  file.   If  number=1,  all  engine  output  is  written
              faithfully  to  the  debug  file.  If number=2, any protocol-violating line is prefixed with a '#'
              character, as the engine itself should have done if it wanted to submit info for inclusion in  the
              debug  file.  This option is provided for the benefit of applications that use the debug file as a
              source of information, such as the broadcaster of live games TLCV / TLCS.  Such  applications  can
              be protected from spurious engine output that might otherwise confuse them.

       -rshor-remoteShellshell-name
              Name  of  the  command  used to run programs remotely. The default is `rsh' or `remsh', determined
              when XBoard is configured and compiled.

       -ruseror-remoteUseruser-name
              User name on the remote system when running programs with the `remoteShell'. The default  is  your
              local user name.

       -userNameusername
              Name  under  which  the Human player will be listed in the PGN file.  Default is the login name on
              your local computer.

       -delayBeforeQuitnumber-delayAfterQuitnumber
              These options order pauses before and after sending the "quit" command to an engine that  must  be
              terminated.   The  pause  between quit and the previous command is specified in milliseconds.  The
              pause after quit is used to schedule a kill signal to be sent to  the  engine  process  after  the
              number  of  specified seconds plus one.  This signal is a different one as the terminiation signal
              described in the protocol specs which engines can suppress or ignore, and which is  sent  directly
              after  the  "quit"  command.   Setting  `delayAfterQuit'  to  -1 will suppress sending of the kill
              signal.  Default: 0

       -searchModen
              The integer n encodes the mode for the `find position' function.  Default:  1  (=  Exact  position
              match)

       -eloThresholdBothelo-eloThresholdAnyelo
              Defines  a  lower  limit  for  the  Elo  rating,  which  has to be surpassed before a game will be
              considered when searching for a board position.  Default: 0

       -dateThresholdyear
              Only games not played before the given year will be considered when searching for a board position

Other Programs You Can Use With Xboard

       Here are some other programs you can use with XBoard

   GNUChess
       The GNU Chess engine is available from:

       ftp://ftp.gnu.org/gnu/gnuchess/

       You can use XBoard to play a game against GNU Chess, or to interface GNU Chess to an ICS.

   Fairy-Max
       Fairy-Max  is  a  derivative  from the once World's smallest Chess program micro-Max, which measures only
       about 100 lines of source code.  The main difference with micro-Max is that  Fairy-Max  loads  its  move-
       generator  tables from a file, so that the rules for piece movement can be easily configured to implement
       unorthodox pieces.  Fairy-Max can therefore play a large number of variants, normal Chess  being  one  of
       those.   In  addition it plays Knightmate, Capablanca and Gothic Chess, Shatranj, Courier Chess, Cylinder
       chess, Berolina Chess, while the user can easily define new variants.  It can be obtained from:

       http://home.hccnet.nl/h.g.muller/dwnldpage.htmlHoiChess
       HoiChess is a not-so-very-strong Chess engine, which comes with a derivative  HoiXiangqi,  able  to  play
       Chinese Chess. It can be obtained from the standard Linux repositories through:

       sudo apt-get install hoichess

   Crafty
       Crafty  is  a  chess engine written by Bob Hyatt.  You can use XBoard to play a game against Crafty, hook
       Crafty up to an ICS, or use Crafty to interactively analyze games and positions for you.

       Crafty is a strong, rapidly evolving chess program. This rapid pace of development is  good,  because  it
       means  Crafty  is always getting better.  This can sometimes cause problems with backwards compatibility,
       but usually the latest version of Crafty will work well with the latest version of XBoard.  Crafty can be
       obtained from its author's FTP site: ftp://ftp.cis.uab.edu/hyatt/.

       To use Crafty with XBoard, give the -fcp and -fd options as follows, where <crafty's  directory>  is  the
       directory in which you installed Crafty and placed its book and other support files.

Reporting Problems

       You    can    report    bugs    and    problems    with    XBoard    using    the    bug    tracker    at
       `https://savannah.gnu.org/projects/xboard/' or by sending mail to `<bug-xboard@gnu.org>'.  It can also be
       useful  to report or discuss bugs in the WinBoard Forum at `http://www.open-aurec.com/wbforum/', WinBoard
       development section.

       Please use the `script' program to start a typescript, run XBoard with the `-debug' option,  and  include
       the  typescript  output  in  your  message.   Also tell us what kind of machine and what operating system
       version you are using.  The command `uname -a' will often tell you this.

       If you improve XBoard, please send a message about your changes, and we will get in touch with you  about
       merging them in to the main line of development.

Synopsis

xboard[options]xboard-ics-icshosthostname[options]xboard-ncp[options]|pxboardcmail[options]

See Also