Duke Nukem Forever is part four in a series of PC games featuring Duke Nukem as the hero. Parts one (Duke Nukem) and two (Duke Nukem 2) were sidescrollers/platform games, and part three, Duke Nukem 3D, was an FPS. Duke Nukem 3D became one of the top-selling games of all time, and is a very important part of FPS gaming history; it is one of the few "legendary" titles, together with Quake and Doom. The game is one of the most sophisticated FPS games ever. It features everything the Unreal engine has, but also features things like LOD, skeletal animation, and motion capture, for an optimal playing experience.
EDM is a fork of Sauerbraten (http://www.sauerbraten.org/) which is in development but playable. It features several multiplayer game modes like Deathmatch and Instagib, dynamic map model physics, enhanced particle effects, unique weapons and powerups, and more. Maps can be edited with other players online.
Excalibur: Morgana's Revenge (EMR) is a first-person shooter game with an epic and in-depth story line. The player travels through time in the Jurassic period, Camelot period, and into the future to chase down Morgana. Using the Aleph One engine, EMR creates an amazing new world, making it an entirely fun and unique gaming experience.
GLOBE_3D is a real-time 3D engine. It features unconditionally portable sources (one set of sources for all platforms), real-time rendering (fast with a 3D hardware-accelerated graphics card), full eye movements and rotations, display of combinations of colors, materials, and textures, transparency, multiple area rendering with the portal technique (e.g. for inner scenes), collision detection, binary space partition (BSP), input-output of 3D objects or groups of objects linked to each other by portals, easy management of resources like textures (.bmp and .tga), BSP trees, and objects stored in .zip files, screenshots (.bmp) and video captures (.avi), multi-view support, and vectorized geometry support.