Networking Support: support for calling REST, WS*/SOAP, POX, RSS, and standard HTTP services. It supports cross domain network access (enabling Silverlight clients to directly access resources and data from resources on the web). Also includes built-in sockets networking support.
Silverlight 2 does not require the .NET Framework to be installed on a computer in order to run. The Silverlight setup download includes everything necessary to enable all the above features. Silverlight 2 is 4.3MB in size