PrBoom+ is an enhanced source port of the classic 3D first-person
shooter game Doom, first released by id Software in 1993. It uses the
Simple Direct Media layer (SDL) library and features an optional OpenGL
renderer. It is based on PrBoom, MBF and LxDoom, which in turn are based
on TeamTNT's Boom, a freely available port of Doom for DOS.
In addition to PrBoom's features, PrBoom+ offers uncapped framerate,
variable gamespeed, re-record, walkcam, chasecam, full mouselook, FOV,
and other features without loss of compatibility with the original Doom.