All-in-one program for creating 2D scrolling games. Compile your games into stand-alone .NET executables or customizable C# source code. The IDE and framework are build on OpenTK, which wraps OpenGL, so generated games can be cross-platform.
A Java framework for writing sprite based games (turn-based, card, and arcade games.) Provides: Sprite management, rendering (Java2d or OpenGL), Collision Detection, Sprite widgets (buttons etc...), visual editor for layout of game widgets.
Prototype Games aims to provide a Javascript library for quickly and easily creating web-based games that run entirely in the web page, on all modern browsers without requiring plug-ins. It is built off of the YUI (Yahoo User Interface).