Virtual machine implementation for visual novel games
ViLE is a collection of interpreters capable of decoding visual novels and dating sims. You can use ViLE as a drop-in replacement for the original executable to play the games, but ViLE also provides exclusive titles and features such as software scaling.
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.