iSDGE is an open source 3D game engine for iPhone, iPad and iPod Touch. It is based on iOS 4 and under steady developement. Currently it only features rendering of 2D and 3D objects and no physics, audio or networking yet. It offers a flexible and easy to use shader system using OpenGL ES 2.0. A powerfull terrain system and a fast stencil shadow implementation. The focus is on speed and especially ease of use. The engine is mostly written in C++ and one small part in Objective-C. iSDGE features its own fast to load model format and comes with a exporter for Blender.
This video shows iSDGEs basic bullet implementation for rigid bodies. This video is recorded from within the simulator and runs faster and looks better on the real device.
so awesome!