Dynamic languages provide an interactive approach to developing Silverlight-based applications. The dynamic language runtime (DLR) enables dynamic languages to run on the common language runtime and to use the .NET Framework class library for Silverlight. The DLR and three dynamic languages (IronPython, IronRuby, and Managed JScript) are currently under development on the Codeplex Web site. You can find more information there, including source code and Silverlight samples.