ZDoom is a source port, originally based on ATB Doom and NTDOOM. It has since added nearly full support for Boom, Heretic, and Hexen, and has made several steps recently to add support for Strife as well (Versions 2.0.90 and above have full support, but possibly some bugs). It has added many additional features, including slopes, uncapped fps (though the cap can be turned back on from the console), and z-clipping. The source code is maintained by Randy Heit. Currently the project is in beta testing, and the most recent version is Template:Latest ZDoom.
- Support for all of Hexen's editing features (including ACS, hubs, and new map formats).
- Support for most of Boom's editing features.
- Support for Strife (WIP).
- Removal of most vanilla Doom limits (including the evil visplane overflow).
- Free look (i.e. looking up/down).
- High screen resolutions (with optimizations for modern processors).
- Translucency (regular and additive).
- A console.
- More music formats: MOD, XM, IT, S3M, MIDI, OGG, SPC, and MP3, as well as MUS.
- Support for PNG format images.
- Support for high-resolution textures.
- Better mouse support.
- Limited UDP Internet or LAN networking inherited from Linux Doom.
- Quake-style key bindings.
- Walking over/under monsters and other things.
- Runs under Windows 95/98, Windows NT, and Linux.
- Support for Doom Connector network games.
- Support for custom player skins.
- Support for sloped floors and ceilings.