D2X is a port of Descent 2 to OpenGL. It is an open source project and has received a lot of enhancements compared to Descent 2.Descent 2 is a pretty old game, and further development has slowed down; so there are a few issues - some still stemming from the original Descent 2 - that have never been addressed or solved in D2X.Source code and level editor available at the Author link above.