Convergence was a game written by Matthew Riche and myself (Julian Squires) in 2002. It was never finished, although the version presented here is not quite the final version. I do plan to finish it and open source the whole thing; for the moment, however, you can consider this repository to be ambiguously licensed: look but don't touch.
This is based on the last snapshot I could find. I do have a DDS-2 backup tape that should contain the whole CVS repository, which I need to dump anyway because it includes some build tools that don't seem to be in this repo.
It is possible to build a ROM that plays in emulators like mednafen (and on the real hardware) from this tree, but it's tricky, and due to the number of strange behaviors I've encountered with the build I've made so far, I suspect there is some subtlety I'm missing (probably a dependency in the tools on a 32-bit machine).
You might find my postmortem on the project of interest, although, like this code, it's very dated.