Known limitations: All traces are black; in the future I plan to use different gray values for different Z depths. Tool size is unspecified; PostScript uses a 1-point wide "pen" by default. In the future I plan to make this customizable, and respond to tool change commands appropriately. Speaking of points, another feature this program needs is ability to specify the units, so output will be to scale. Right now it assumes the units are points. There are many G-codes; so far only G0 - G4 are implemented (moves, line segments and arcs).
The code has been moved to Google Code. Here's a mirror of version 0.2.0 just in case.