- id Software
They wrote some software; I forgot which...
- Doom Explorer
A fine alternative Doom launcher created by Bond.
- Flash Doom 2D
A 2D platform game inspired by DooM and implemented in Flash
by knarrenheinz. What can I say? Run.. don't walk.
The largest WAD server in the world by Mega-Dog & Rygrass.
Your online resource for Classic Doom2 information, files and
links hosted by Bahdko.
- The Doom Wiki
Documentation about anything related to Doom and Doom II,
as well as games based on the Doom engine.
A free alternative to commercial IWADs.
- Doom Help Service
Lots of general information about the Doom family.