Is there Silverlight toolkit for specifically for its browser plugin?
Silverlight Toolkit is an add-on that contains samples and open source code. It helps you to develop Silverlight products better and faster. This is not an add-on for a browser rather than a pack with various development resources and items to help you to achieve what you want through Silverlight technology. You can check for the supported components using the following URL: http://silverlight.codeplex.com/releases/view/78435