Agar is a high-level graphical C application framework aimed primarly at 2D/3D games and simulations. Agar applications are portable to a variety of operating systems thanks to the Simple DirectMedia Layer library. Among other things, Agar implements an object system (persistence, memory management, dependencies, etc), a complete widget set and tile-based levels.
One of the major goals of Agar is to allow non-programmers to create games using graphical edition tools.
Agar is open source, released under a BSD license, which allows the engine to be used by commercial games.
The engine is in development since early 2002. Trek to the Cave, a 2D role-playing game in the spirit of Square SNES games, uses the Agar engine.