Doom was the classic 3D shoot'em'up game from id Software. PrBoom is a game engine for playing Doom levels, which runs on both Windows and Linux/Unix systems. It uses the SDL graphics library. PrBoom a very faithful Doom port, with great effort taken to be compatible with as many original Doom levels and demos as possible.
Quake 2 Map Info is a command line utility that parses a Quake 2 map file and reports how many entities and textures are being used. It is useful for spotting extra items to improve gameplay balance and/or reducing extra textures to increase map speed. Most map editors do not provide a detailed breakdown of what is inside a map. It is compatible with any Quake 2 (ID Tech 2) game engine if the map file format has not be altered. If a game has a different map format, you can modify the source code to reflect the new format.
UProxy is a proxy for UDP protocols. UProxy was initially designed to allow users to play Unreal Tournament matches over the Internet on computers sharing a dial up connection. It could also be used by any client-server application that uses the UDP protocol and doesn't require clients to bind a fixed port. UProxy should run under Windows, Linux, or any OS which supports BSD sockets.
Warsow is a standalone, eSports-oriented FPS game. It is based on Qfusion, an advanced modification of the Quake 2 engine. It features fast-paced gameplay focused on trix (trick jumps) and art of movement. War§ow features a complete power-up system, including weak and strong fire mode for each weapon in all "normal" gametypes as well as Warshell (battle shield) and Warshock (quad damage) for team-based gametypes. Its cartoonish graphics use cel shading with a style that is similar but not identical to Manga.