Moonlight 2.0, which is open source software that puts Microsoft's Silverlight rich Internet application technology on Linux, has been offered up as a beta release.

The beta release follows a preview version done in May, said the developer, Miguel de Icaza, who has shepherded the project at Novell.

"This means that Moonlight 2.0 is now feature-complete and we consider it ready to test against Silverlight 2.0 sites. Users who have installed Moonlight 2.0 previously will be offered a chance next time they start Firefox to upgrade to the beta," de Icaza said.

Moonlight trails Microsoft's Silverlight 3 in functionality, he said. The API implemented by Moonlight 2.0 is a super-set of Microsoft Silverlight 2.0. Silverlight 3 was released last month.

"Although Microsoft has already released Silverlight 3.0 with new functionality and APIs, it will take some time to be fully adopted, so while we might be behind Microsoft's offering, we still think that this will allow users to access most Silverlight content out there today," de Icaza said.

Some Silverlight 3 APIs are included though, including MultiScanImage 3.0 API enhancements and SaveFileDialog. Moonlight 2.0 does support the Silverlight 3.0 media pipeline allowing developers to use C# code at different points in the media playback process, de Icaza said.

"In particular, this means that you can use Silverlight and Moonlight with the Mono project's OGG, Vorbisand Dirac codecs to play back media files that use the open codecs or to plug your own media codecs," he said. Dirac backing remains a work in progress.