moo.fx 2.0 released with Fx.Style while Animator.js avoids inheritance
It's very easy to use, blazing fast, cross-browser, standards compliant, provides controls to modify any CSS property of any HTML element, including colors, with builtin checks that won't let a user break the effect with multiple, crazy clicks. Optimized to make you write the lesser code possible, the new moo.fx is so modular you can create any kind of effect with it.
Bernie Sumption introduces Animator as an easy-to-use animation class with a small file size that uses composition and parameterization instead of inheritance. It was written as an alternative to moo.fx and Script.aculo.us because Sumption felt strongly about the decision to use inheritance:
In particular, they don't seem to realise that inheritance is evil, and must be destroyed. By providing base classes for an effect and requiring users to subclass it to make new effects, they create a proliferation of classes and make it too hard to create new effects that the library designer hasn't thought of (scriptaculous gets round this by thinking of every effect you might want, which is why it is so large).
Hi InfoQ readers
Another much wished-for feature is the ability to set the to and from states of an animation using CSS class names so that you can keep all of your style information in one place.
If any of you have any other things you'd like to see developed, let me know on this page.