The Dojo foundation has released version 1.0 of the Dojo javascript toolkit. Dojo is one of the most complete javascript toolkit available, with of course ajax functionalities but also internationlisation, cryptography, offline capabilities and a widget system. It supports Firefox, Safari, Internet Explorer and Opera browsers.

It is used in products by AOL, BEA, IBM and Sun amongst others.

Yui Compressor, as the name wouldn't suggest, is not working only on YUI, but is a general javascript compressor based on Rhino, the Javascript interpreter implementation in Java, included in Java 6.