Hardware requirements are a sampler that slots into the parallel port, a recorder for ign.pulses (A cassette deck does fine as long as it keeps the speed right), and a wire to connect to the ignition coil. This wire is detailed in the .lzh and the package also has an example file.
The current version is v2.0, further revisions will be scarce due to development being shifted towards RevPro.
The source for the program isn't available because of it's length (4500 lines) would make it impossible to understand and I don't have the time and energy to describe it to anyone. Besides it would probably just end on the hands of some money-hungry jerk trying to get profit, which is not the general idea with this program.
For more information, click here.