http://easysl.codeplex.com/ 
http://compositewpf.codeplex.com/

http://silverlight.codeplex.com/releases

OpenSource Porject:

1. Siverlight ToolKit (OpenSource)

http://www.codeplex.com/Silverlight

   补充: Silverlight Toolkit March 2009 changes

2. GOA ToolKit for Silverlight (OpentSource)

http://www.netikatech.com/downloads

3. Silverlight Contrib (OpenSource)

http://silverlightcontrib.codeplex.com/

4. Silverlight Extension (OpentSource)

http://slextensions.net/

5. Silverlight FX(OpenSource)

http://projects.nikhilk.net/SilverlightFX/

6. SilverLight BlackLight (OpenSource)

http://blacklight.codeplex.com/Release/ProjectReleases.aspx

7. Visifire For Charts(OpenSource)

http://www.visifire.com/

Third Party Controls:

1. ComponentOne

http://www.componentone.com/SuperProducts/StudioSilverlight/Live+Examples/

2. Devexpress

http://demos.devexpress.com/Silverlight/

3. Infragistics

http://www.infragistics.com/dotnet/netadvantage/silverlight/line-of-business.aspx#Overview

4. Telerik

http://www.telerik.com/products/silverlight.aspx

5. ComponentArt

http://silverlight.componentart.com/

6. divelements

http://www.divelements.co.uk/

Silverlight开源项目与第三方控件收集