Moonlight, the open source Silverlight implementation for Linux, has been sent to manufacturing. It can be downloaded as a Firefox plug-in running on most Linux distributions. Moonlight 1.0 uses Microsoft Media Pack 2 to play the media files.
Like Silverlight, Moonlight 1.0 does not play the media files by itself but relies on Microsoft Media Pack 2 to play them. The necessary codecs are downloaded and installed when the browser hits a page with such media for the first time. Initially, support for Media Pack 2 was planned for version 2.0, scheduled for production in September this year. Version 2 will contain .NET support for added functionality. Miguel de Icaza considers that Microsoft helped them a great deal by open sourcing a number of projects:
They [Microsoft] have open sourced the Microsoft DLR, the Microsoft MEF framework and the crown jewels: the Microsoft Silverlight Control Library and the Control Toolkit under the OSI-approved MS-PL licenses. Without this it would have taken years for us to catch up.
Moonlight is available for Linux/i586 (32 bit) and Linux/x86 (64 bit) as a Firefox 2 or 3 plug-in. At 0.9 MB, it is much smaller than the 4.6 MB Silverlight 2 Windows installer. The complete list of platforms supported details the exact operating systems on which it was tested, but it is expected to run on all major Linux versions, and Miguel added “we are also hoping to expand our reach to other Unix variants that use X11 like the various BSD systems and Solaris and make codecs available for those”. While Moonlight is not supported and does not run on Google Chrome, Tim Hauer has posted a hack that makes it work.
More information on Moonlight is available at InfoQ/Moonlight.