Important: We are releasing only the Silverlight Developer Runtime edition (as well as the VS and Blend tools to support it) today, and are not releasing the regular end-user edition of Silverlight.  This is because we want to give existing developers a short amount of time to update their applications to work with the final Silverlight 2 APIs before sites are allowed to go live with it.  There are some breaking changes between Beta2 and this RC, and we want to make sure that existing sites can update to the final release quickly once the final release is out.  As such, you can only use the RC for development right now - you can’t go live with the new APIs until the final release is shipped (which will be soon though).

You can download today’s Silverlight Release Candidate and accompanying VS and Blend support for it here.  Note that Expression Blend support for Silverlight 2 is now provided using Blend 2.0 SP1.  You will need to install Blend 2.0 before applying the SP1 service pack that adds Silverlight 2 support.  If you don’t already have Blend 2.0 installed you can download a free trial of it here.

Beta2->RC API Updates

Today’s release candidate includes a ton of bug fix and some significant performance optimization work.

Today’s release candidate also includes a number of final API tweaks designed to fix differences between Silverlight and the full .NET Framework.  Most of these changes are relatively small (order of parameters, renames of methods/properties, movement of types across namespaces, etc) although there are a number of them.  You can read this blog post and download this document to get a listing of the known API breaking changes made from the Beta2 release. 

We have updated the styles of the controls shipped with Silverlight, and have also modified some of the state groups and control template names they use.  When upgrading from Beta2 you might find it useful to temporarily remove any custom style templates you’ve defined, and get your application functionality working using the RC first - and then after that works add back in the styles one style definition at a time to catch any rename/behavior change issues with them.

If you find yourself stuck with an question/issue moving from Beta2 to the RC, please report it on the www.silverlight.net forums (Silverlight team members will be on there helping folks).  If after a day or two you aren’t getting an answer please send me email (scottgu@microsoft.com) and I can help or connect you with someone who knows the answer.

New Controls

Today’s release candidate includes a bunch of feature additions and tweaks across Silverlight 2, as well as in the VS and Blend tools targeting it. In general you’ll find a number of nice improvements across the controls, networking, data caching, layout, rendering, media stack, and other components and sub-systems.

Over the next few months we will be releasing a lot of new Silverlight 2 controls (more details on these soon).  Today’s release candidate includes three new core controls - ComboBox, ProgressBar, and PasswordBox - that we are adding directly to the core Silverlight runtime download (which is still only 4.6MB in size, and only takes a few seconds to install):

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You can learn more about how Silverlight’s Visual State Model works from my previous blog post here. 

Previous releases of Silverlight often rendered graphics on sub-pixel locations - which could cause lines and shapes to sometimes appear “fuzzy”.  The RC of Silverlight has a new features called “layout rounding” that causes the layout system to round the final measure of a control to an integer (”pixel snapping”), which results in crisper lines and fewer rendering artifacts.  This feature is now on by default, and helps make applications look nicer.

Summary

The final release of Silverlight is not that far off now.  It has been a pretty amazing project that has come a long way in a pretty short amount of time.

If you have existing Beta2 applications, please start getting them ready for the final release - as once we release Silverlight 2, users that have existing beta releases installed will automatically be upgraded to use the final version.  Testing your application out with the release candidate will ensure that you can easily update your applications and have them ready within hours of the final release.

Let us know if you find issues with today’s release candidate, and please make sure to post them on the forums on http://www.silverlight.net.

Hope this helps,

Scott