The original Wolfenstein 3D code was written in late 1991 / early 1992 using 16 bit Turbo C and the TASM assembler and targeted at 286 based MSDOS systems with VGA graphics and ideally a bit of extended or expanded memory.
"I can't say there is a lot of really good code here -- the wolf code is mutated, the quake 2 code is vestigial, and the new code was written in a hurry, but it does all hang together as a pretty fun game to play, and a good testbed for various things. If anyone does build another quality commercial application based on this code, let us know, and we can probably do some kind of cross linking."