I'm naming the new avatar framework Avatar Core. It will be (isn't yet) hosted on Google Code under MIT, just like My Avatar Editor. In fact it will essentially be under the My Avatar Editor umbrella, using www.myavatareditor.com as its home page - of sorts.
I've got a new, very simple Avatar Core demo online using a couple of the Mii character assets from My Avatar Editor. Like My Avatar Editor, it consists of two SWF files, the editor (seen in demo link), and the viewer. The editor loads the viewer, reads its definition (which it, in turn, loads from this XML file), and provides appropriate selections. Both the editor and the viewer were written in less than 100 lines of code each (not counting the Avatar Core framework). Because of the flexibility of this framework, you could potentially grab these SWFs now, put them on your server, and use your own XML definition and graphics to completely change the avatar and all of its features including what it displays and what it could potentially display as well as the options provided in the editor interface.
There have been a few changes in the XML since the last post. The most important are a couple of new features including default transforms and parent definitions. A transform represents how an avatar feature looks (position, scale, rotation). A default transform lets you specify a start transform when a feature is added to an avatar for the first time. Not a big deal, but helpful in terms of having these settings defined in the XML. Before, transform properties were only defined directly within avatar features. Now they exist within a separate transform object.
Parent definitions are definitions that another definition is attached to. Consider an earring on an ear. Both are separate features, but if an ear moves up and down the side of an avatar's head, that earring should follow it. By specifying the ear as being a parent to the earring definition, when the ear moves, so will the earring.
There have been some other naming changes and enhancements to reduce XML verbosity as well. I'm not sure if this will be the final format, but I think it's looking pretty good right now.
Moving forward I'll probably focus on more avatar/editor examples using more features (such as constraints and colors). This will hopefully also flush out any bugs if they exist.