What is the OpenAjax Hub?
The OpenAjax specification v1.0 is available at OpenAjax Hub Specification.
The specification for v2.0 of the Hub is under development at OpenAjax Hub Specification. This version adds secure mash-up functionality, including secure cross-domain communication within the browser.
An open source reference implementation, along with conformance tests, is available at http://sourceforge.net/projects/openajaxallianc.