GlDoom

glDoom (created and maintained by Bruce Lewis), based on WinDoom, was the first source port to add OpenGL support to Doom. Before beta testing could be completed and the source code released publicly, the source was lost to a hard drive issue. The last glDoom version was released on December 23, 1998.

In April 2010, glDoom reappeared on SourceForge. The author discovered copies of the source code on the computer of a late friend of his. This resurrected version of the source code, however, was probably not the latest version (some features which work in the released binary no longer did) and had to be updated to compile with newer development environments. The ninth and last update to its SVN repository was made on October 8, 2010.