Welcome to diyCAM.
After building my own CNC Router and starting to get into the necessary software, I was disappointed by the relatively small selection of inexpensive but still capable options available. diyCAM is my attempt to correct that, starting with diyCAM: Carve, which makes it quick and easy to generate GCode to create carvings on your CNC Router from a heightmap.
At the request of a friend who also built his own CNC, the next program I plan to write will be GCode Viewer, with the ability to load multiple GCode files, simulate them carving a mesh, manipulate them slightly (translate, scale, etc), apply realistic materials, and select parts to drill into the exact line of GCode involved with that part of the path.
Finally, sometime after that (and hopefully not too far off) my goal is to create a vector based 2.5D CAM app. My goal is that, coupled with diyCAM: Carve, this would allow hobbyists to handle nearly all CAM related tasks for around $100.
-Matt Mitman, creator of diyCAM