ldescent - Mailing list archive, source code, and binaries. Project has been superceded by d1x. - http://www.arbruijn.dds.nl/ldescent/
Freshmeat - Project page for DX1, a modification of the Descent 1 source that was released by Parallax. Contains details and information. - http://freshmeat.net/projects/d1x/
Loki Games - Linux port for Descent 3. - http://www.lokigames.com/products/descent3/