Scratch - Scratch is the programming language & online community where young people create stories, games, & animations.
Cyberix3D - Free online 3D Game Maker. Make your own 3D games online!
EduBlocks - Making the Transition from Scratch to Python easier.
Open 3D Engine - Open 3D Engine is an open-source 3D game development engine in real-time.
Bingo - Programming language based on Scratch, which uses a "block" UI for building apps and...
Castle Game Engine - An open-source 3D/2D game engine for ObjectPascal.