Moonlight 3.0 that puts Microsoft’s Silverlight rich Internet plug-in software on Linux and UNIX platforms is now being offered in an alpha release, according to Web pages from the Mono project, which has jurisdiction over Moonlight.

Novell, which sponsors Mono, said the release features infrastructural capabilities designed to move Moonlight closer to the capabilities of Silverlight 3.

Novell VP Miguel de Icaza, who has been in charge of Moonlight and Mono projects, described the release as the first preview of Moonlight 3.0 in a blog posted this week.

Capabilities include MP4 demuxer support, although there are no codecs for it yet unless a developer builds them from source code and configures Moonlight to pick up codecs from ffmpeg.

Also featured is initial work on UI virtualization and a platform abstraction layer. The Moonlight core is now separated from the windowing system engine. This should make it possible for developers to port Moonlight that are not X11/Gtk+-centric, according to de Icaza.

The alpha release features 3.0 Binding/Binding Expression support and updates to APIs. An SVN (Subversion) of Silverlight 3.0 offers pixel shader support from developer David Reveman.

A beta version of Moonlight 3.0 is due this summer, followed by a final release in the fall, according to Novell. A download page for Moonlight 3.0 stresses that the project is only in an alpha stage and offers caution.

According to the page, this release should be considered alpha quality. There are various new subsystems in Silverlight 3 which expose new and different attack vectors, and the implementations of these subsystems have not yet been exercised or audited.

The page recommends that one should use this plugin on trusted sites on non-production computers. This situation will gradually evolve over the beta releases. According to the page, an up- to-date overview of Moonlight security features status can be found on Moonlight Security Status wiki page.