PrBoom+

PrBoom+ (also PrBoom-plus) is a source port based on PrBoom, GLBoom+ is its associated OpenGL variant, both developed by Andrey "entryway" Budko.

PrBoom+ features, among other things, an uncapped framerate and a chasecam for demo playbacks. PrBoom+ was recently upgraded to the PrBoom 2.5.x line of development. It can currently be compiled in POSIX, Windows and Mac OS X environments.