HGE!

Pygame is a set of Python modules designed for writing games. Pygame adds functionality on top of the excellent SDL library.

OGRE (Object-Oriented Graphics Rendering Engine) is a scene-oriented, flexible 3D engine written in C++ designed to make it easier and more intuitive for developers to produce applications utilizing hardware-accelerated 3D graphics. Since 2001, OGRE has grown to become one of the most popular open-source graphics rendering engines, and has been used in a large number of production projects, in such diverse areas as games, simulators, educational software, interactive art, scientific visualization, and others. »

Cross-platform windowing and multimedia library for Python.

A platform independent 2d game programming framework for c/c++ programmers with least possible dependencies for easy porting and with focus on easy API calls and the requirement of commercial programmers.

Arianne is a multiplayer online games framework and engine to develop turn based and real time games. It provides a simple way of creating games on a portable and robust server architecture. The server is coded in Java and you may use Python for your game description, provides a MySQL or H2 database backend and uses an TCP transport channel to communicate with hundreds of players.

Amulet is a Lua-based toolkit for experimenting with interactive graphics and audio. It provides a cross-platform API for drawing graphics, playing audio and responding to user input, and a command-line interpreter for running Amulet scripts.