ENIGMA is a free game and application development toolkit, utilizing GCC and a series of parsers to convert a high level, script-like language based on Game Maker's GML, into C++. The toolkit employs a mixture of both C++ and GML, accepting either.
JFrog is a free distributed components-oriented framework created to develop multiplatform game engines with high source code reusability. Its possible to create game engines for personal computers and handhelds. Before this project was Amphibian.
World Foundry is a 3D level game engine and asset production pathway with over 170,000 lines of code. Originally a commercial product, now released under the GPL. Designed from the beginning to be cross-platform, runs on windows, working on linux port.
It is a point a click game creator that is based off the TrueVision3D engine. The creator will allow the user to create a 3D or 2D game in a gui interface. The software will then generate code that can be edited, or compiled into a functional game.