[GEBEN commands]

Execution:
 g     run
 i     step into
 o     step over
 r     step out
 q     stop debugging

Breakpoints:
 b     set breakpoint on current line
 B     set breakpoint at specified function or exception
 u     delete breakpoint on current line

Examining and changing variables:
 e     eval a PHP expression, prints to *Messages* buffer

Stack:
 d     print stack trace, move up and down
 w     go to current line
 v     view locals and superglobals

Help:
 ?     geben mode help

To disable displaying this help screen set Help option in the [Emacs] 
section of your ~/.phpsh/config file to "no".
