You can check out the source code in SVN. There is still a lot of work to do, but both the demo and full game run great. If you don't already own the full game, you may have a hard time finding it for sale, as copies of the game are pretty scarce these days. Be sure to apply the 1.2 patch for the full version, if you have not already. If you just want to try the demo, you can download it from places like here or here (you don't have to apply the patch for the demo).

A mailing list, freespace2@icculus.org, exists for the project; to subscribe, send a blank email to freespace2-subscribe@icculus.org.