Among the things that seem interesting about Google Closure are:
- They've gone with a templating approach. Templating approaches seem to come and go, dating back to things like ASP and JSP last century, and probably older systems before that -- I think ColdFusion was a templating system.
Since this library is from Google, you can be sure that it is thorough, powerful, and sophisticated, and therefore worthy of study.
I guess that means I've got something else to learn about now!