LxDoom was a Doom port developed by Colin "cph" Phipps, initially as a Linux port of Boom, but later extended to a general POSIX port. It included support for The X Window System and SVGALib (in a separate executable called lsdoom), following the trend of the original Linux port of Doom.
Eventually, the LxDoom and PrBoom projects merged. Because of its portability, bug fixes and strong backwards compatibility, LxDoom formed the basis for the new version of PrBoom. The new version is based on LibSDL, which makes it quickly portable to many different operating systems.