Pd is a graphical programming environment for real-time audio synthesis and related applications. It
sports a rich set of real-time control and I/O features.
To get a list of allowable arguments to pd, type
pd-help
and for more documentation either start pd and get help, or consult
http://msp.ucsd.edu/Pd_documentation/index.htm
or seek a copy on your own machine. On Debian, if you have installed the puredata-doc package, you
should be able to find it in
file:///usr/share/puredata/doc/1.manual/index.htm