Cube 2

http://sauerbraten.org

Cube 2: Sauerbraten (German for "sour roast", also known as Sauer) is a cross-platform, Quake-like first-person shooter that runs on Microsoft Windows, Linux, FreeBSD and Mac OS X using OpenGL and SDL. The game features single-player and multiplayer gameplay and contains an in-game level editor, its main feature. The game engine is free and open source software, under the zlib License,^[2] with commercial support available from the developer's own business counterpart, Dot3 Labs.^[3] The game media is released under various non-free licenses. The aim of the project is not to produce the most features and highest-quality graphics possible, but rather to allow map-editing to be done in real-time within the game, while keeping the engine source code small and elegant.

The game started as a redesign of the original Cube game engine,^[4][5] and its first, developer-only, release was made on February 27, 2004.^[6] The latest release, dubbed the "Justice Edition", debuted on July 19, 2010,^[7] adding two new player models, thirty new user-created maps, several new game modes, including Efficiency CTF, Efficiency Hold, Efficiency Protect, Hold, and InstaHold; a mini-map, clock, and crosshairs, among various other things.