openDarkEngine is a from-scratch rewrite of the famous Dark Engine originally written by Looking Glass Studios. The engine was used in the Thief 1, Thief Gold, Thief 2, and System Shock 2 games. This rewrite is targeted at newer machines and should improve compatibility and give the games (and all the fan made material) a never ending life. It should also allow manipulation of the original data files.
The Cafu Engine is an all-purpose, modern 3D graphics engine and game development kit. It is feature complete to get you started quickly. It can be used to create a variety of 3D applications, including games, simulations, and training and architectural software. Written in C++, the tools, libraries, and framework have been designed to make the development of new games and other 3D applications easy. They are actively and continuously developed in order to provide the latest technology.
Revised is a visual editor (or wizard/assistant/GUI) for Ren’Py, the visual-novel game editor. Ren'Py has a lot of capabilities, and Revised's purpose is not to allow everything that Ren'Py can do, just some of the basics. You can think of it as a step-by-step wizard to create the skeleton of a Ren'Py game.
jMonkeyEngine is a game engine made for developers who want to create 3D games following modern technology standards. The framework is programmed entirely in Java, and aimed at wide accessibility and fast deployment to desktop, Web, and mobile platforms. It is not a visual “RPG Maker” or a drag-and-drop “FPS mod”. If you are comfortable writing Java code, you can rely on jMonkeyEngine as your next 3D game’s foundation.