Chocolate Doom

[+Acyclitor+]

http://chocolate-doom.sourceforge.net/

nostalgia that functions

[The Undertaker]

a source port which aims to reproduce the behaviour of the original DOS Doom executables as closely as possible
Is called PrBoom.

[Grazza]

Prboom is great, but it doesn't reproduce absolutely all the Doom(2).exe bugs, doesn't allow saving while using the complevel to emulate Doom(2).exe, and the start-up behaviour is rather different, making it difficult to get a quick start. So there is certainly a place for Chocolate Doom.