Tesseract is a first-person shooter game focused on instagib deathmatch and capture-the-flag gameplay as well as cooperative in-game map editing.

Tesseract provides a unique engine derived from Cube 2: Sauerbraten technology but with upgraded modern rendering techniques. The new rendering features include fully dynamic shadows, global illumination, HDR lighting, deferred shading, morphological/temporal/multisample anti-aliasing, and much more.

Tesseract's engine is open source with a permissive zlib-style license. Tesseract's media content is individually licensed and includes a mixture of public domain, Creative Commons, and possibly non-commercial licenses.