OpenSource Porject:
1. Siverlight ToolKit (OpenSource)
http://www.codeplex.com/Silverlight
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/