Microsoft today announced the release of Silverlight 1.0 which has been available as a beta for quite some while. (Silverlight 1.1 which contains parts of the .NET framework is still in Alpha).
Along with the announcement Microsoft commits Linux support and therefore has partnered with Novell.
This means that Silverlight now has support on all 3 major OS platforms.
Microsoft’s famous Scott Guthrie has covered what’s going on with Silverlight in his in depths blog post.