Introduction You might have noticed that the Silverlight 5 (Release Candidate) is out. One of the new features included in the RC is the ability to call P/Invoke. In this short demo, we will write a Silverlight 5 application that uses the feature. Tools needed: Visual Studio 2010 SP1 or Visual Web Developer Express 2010 SP1 is required to develop a Silverlight 5 RC Application. After you have installed VS2010 SP1 or Visual Web Developer Express 2010 SP1, then you will need to download and install the Silverlight 5 (Release Candidate) Tools for Visual Studio 2010 SP1.