A group pushing interoperability between competing AJAX tools and widgets has claimed a wave of certification, although results are far from clear. The OpenAjax Alliance Monday claimed the "successful interoperability of two key technologies with more than a dozen AJAX products". The technologies in question are an Alliance …
Clarification on Lightstreamer
Details on what Lightstreamer exactly did to pass the 2008 InteropFest are available from the official Openajax Alliance wiki: http://www.openajax.org/member/wiki/2008_InteropFest
The 2008 InteropFest requirements are very clear and I don't see much space for arbitrariness here. In particular, Lightstreamer made publicly available a zip file containing the OpenAjax Metadata for its Web Client library.