Just curious, what right now are some legitimate Ext alternatives and competitors? I was talking with a coworker about my preference for Ext for all things when it comes to RIA's, and he made the remark that "not everything has to be done in Ext." I responded that I didn't know of any frameworks nearly as robust or mature as Ext, and most of the frameworks I've seen consist of a lot of widgety things and none seem capable of doing things like Ext's layout manager does. Thoughts?