From Philippe Elsass:
Away3D lite with new Stage3D Renderer for Flash 11, while still keeping full FP10 compatibility. With a single SWF you can render the same scene both in a Flash 10 player and a Flash 11 player with Stage3D without writing much engine-specific code.
The goal is to have a rudimentary (but simple and fast) Stage3D renderer for simple 3D scenes.
Sparticle File Format (AWP). One of the best particle format for Flash now with importer for SEA3D Studio.
TV goes Stage3D!