What is the best Actionscript3 3D Engine?

Question

I am looking for a somewhat detailed explanation of which 3D Engine for Actionscript3 is the most efficient, practical, scalable, documented, community supported, etc. When

Answer 1

the BEST one really is Alternativa3D, but you have to pay them for it. It's the only one that currently supports FP10 features, as we're still waiting on PapervisionX