ZDoom

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 rate, and z-clipping. The source code is maintained by Randy Heit and Graf Zahl. Currently the project is in beta testing, and the most recent version is 2.2.0.

Features

 * 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.
 * Removal of most vanilla Doom limits (including the 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.
 * Support for DECORATE script.
 * Better mouse support.
 * Limited UDP Internet or LAN networking inherited from Linux Doom.
 * Quake-style key bindings.
 * Jumping/Crouching.
 * Crosshairs.
 * Walking over/under monsters and other things.
 * Runs under Windows 9x, NT, XP, and Linux.
 * Support for Doom Connector and Player Connector network games.
 * Support for custom player skins.
 * Support for sloped floors and ceilings.
 * Skyboxes.
 * Support for loading DeHackEd patches directly.
 * Support for friendly monsters.
 * Support for loading resources directly from ZIP files, making the use of the traditional WAD file optional.
 * Support for .PK3 files instead of .WAD files.
 * ENDOOM and Start up screen (like Hexen's animated one) support

Ports based on ZDoom

 * bZdoom
 * csDoom
 * GZDoom
 * Skulltag
 * ZDaemon
 * ZDoomGL