XAJA is set of libraries that covers all parts of modern web applications development. It is not intended to be a set of "world changing" features, although I believe that some solutions are pretty cool. The idea is to introduce a set of standard practices with supporting set of tools that are reliable and easy to learn.

Actually, the idea is to make a web UI development as close as possible to desktop approach.
The solution is to follow those three basic mechanisms:

Custom Controls
Data Binding
Server Objects access

You can immediately start to build complex applictions using all of these techniques together. Or choose just one of them, integrate with any other technology, or replace any of default parts by your own implementation. In this very first version, server-side libraries are implemented only in .NET however any other server technology could be easily integrated due to simple communication standard.
XAJA Basics