Last week Fuse was released open source.
Fuse is an ActionScript 2 animation & filter management tool.
It is a classlibrary which support various kinds of animation and filters by code. I have tried it out and can say it works like a charm. What I am missing are strongly typed callbacks and strongly typed property lists but the 2.0 sounds not far away.
I don’t had a look at the details but Fuse seems to be very leightweight and is easy to use. An alternative would be the AnimationPackage which has a bigger footprint and perhaps more possibilities.