A first glance of the docs I see the components aspire to a declarative style (being defined entirely in JSON). I'm wondering though, why not use composition[1] instead of inheritance? I need to take a better look to see how view composition would work in FOAM.. But I can tell from experience with Backbone, that using composition instead of inheritance improves code structure and increases maintainability. If composition was a first-class construct (like they made extendsModel), it would get a lot of issues out of the way.

[1] http://en.wikipedia.org/wiki/Composition_over_inheritance