Noddybox
- viDoom editor for DOS, with source code.
- http://www.noddybox.co.uk/gamedev.php?I=vidoom

Slump
- A random map generator for FreeDoom. Offers the current version and release history.
- http://www.samiam.org/slump.html

SLIGE
- Computer generated levels. Screenshot, description and download.
- http://www.doomworld.com/slige/

Enjay's little place of Doom
- Personal site with a guide to sprite editing and using Dehacked.
- http://www.btinternet.com/~Enjay001/

Doom Builder
- An advanced Doom, Heretic and Hexen map editor.
- http://www.doombuilder.com/

XWE
- eXtendable Wad Editor, which edits levels and associated resources for Doom levels and a range of other games.
- http://www.doomworld.com/xwe/

glBSP
- New standard for Doom nodes data needed for OpenGL rendering, and the node building tool to produce this data.
- http://glbsp.sourceforge.net/

Yadex
- A level editor for Unix and Linux systems which supports the Doom games, the Doom betas, and Heretic, Hexen and Strife too.
- http://w3.teaser.fr/~amajorel/yadex/

ZenNode
- Fast nodes and reject builder, for Windows and Linux.
- http://www.mrousseau.org/programs/ZenNode/

Why
- Discontinued editor for Linux and Windows, which supports python scripting.
- http://www.hut.fi/~jpakkane/why/

SBSoftware
- Free download, help, and online registration for DeePsea, a fully featured Doom editor for Windows.
- http://www.sbsoftware.com/

DeuTex
- WAD composer tool, which can extract all types of data from WADs, and build WADs from a collection of resources.
- http://www.teaser.fr/~amajorel/deutex/

BSP
- Node builder, with downloads and documentation available.
- http://doombsp.sourceforge.net/