[naner]

http://en.wikipedia.org/wiki/Doom_3#Doom_3:_BFG_Edition

The BFG Edition features enhanced graphics, better sound with more horror effects, a checkpoint save system, and support for 3D displays and HMDs.

Also on the Doom wiki:

http://doom.wikia.com/wiki/Doom_3_BFG_Edition

[AlexMax]

The community fork of Doom Wiki tends to be a little bit better up-to-date on the whole:

http://doomwiki.org/wiki/Doom_3:_BFG_Edition