I've tried using opencamlib through heekscnc. With a few minor modifications to the ocl_funcs.py script I got it working. Although ocl prints some debug information and a progress bar to the console when run standalone, I couldn't find that window in heekscnc. Even with this small example there are obvious issues with memory management (sometimes 8 Gb wasn't enough!) on either the heekscnc or ocl-side of things (or both!).
On Ubuntu 10.04LTS getting all the bits and pieces, compiling them and installing them was a breeze thanks to this install script. However the GUI feels very "sticky" with the mouse cursor not really going where I want it to go, and the keyboard focus being in surprising places when I want to edit properties. It must be possible to make a GUI that feels good to use with wxgtk, right?
I think currently the inputs and outputs of these two operations, "ZigZag" and "Waterline", are defined in at least three places: ocl itself, the python script ocl_funcs.py, and in the heekscnc c++ GUI code that displays the menus and buttons. Something like introspection or reflection or naked objects would be needed so that a GUI can query the libraries that are present on what operations they offer, what input they need, and what output they produce. If I get my head around some generic-enough GUI ideas I might try writing something myself also. Most probably based on Qt and VTK. In any case the cutting-simulation needs to be driven from a C++ GUI, for performance, I think.