[codeape]

What would it take to add IE8 support?

[EvanYou]

It makes heavy use of Object.defineProperty to achieve the plain object syntax instead of dirty checking. Unfortunately in IE8 Object.defineProperty only works on DOM objects and there's no way to shim it for plain JavaScript objects.

[ams6110]

Why would a new JS framework bother to support a browser that's 3 major revs out of date?

Edit: Possibly you are being sarcastic....

[codeape]

No not sarcastic. Just wondering.

[ianstormtaylor]

You'd need to move to an event-based system like Backbone that emits change events on models.