Integrated Development Environment for PostScript (IdePS)
wxGhostscript is a wxWindows class which wraps access to the Ghostscript DLL (shared object/library), hiding the differences between platforms.
IdePS is a system for developing programs written in PostScript, and provides an editor and a debugger. It also forms a worked example as an aid to anyone looking to use Ghostscript from within their application.
The IdePS debugger works by "instrumenting" the code under test. That is, it inserts a call into the debugger before every operator, which gives the debugger a chance to decide whether to break at any point or to continue. This means you can feed a PostScript file containing procedures or procedure sets into the debugger, and then run a PostScript file for rendering normally. Having set breakpoints in your procedures, you can then run other PostScript files, examining the state of the PostScript VM's stacks, etc. when execution is suspended at one of those breakpoints.
The debugger itself is written in PostScript, which mean that (theoretically at least) it could be made to run under other PostScript interpreters.
Links for more information:
Project summary page
If you are interested in joining/contributing to the project, please send a message.