Silverlight and WPF are not the same things, but related. WPF is a Windows-based technology. Silverlight is a subset of the .Net framework and runs in a browser (IE, Firefox, Safari) and on Windows, Mac, and Linux.

>I wonder, how can it be? My understanding (I admit, very limited) that Silverlight carries .NET framework so that the application can run in a browser without having .NET installed. And I can't say that .NET is light. In fact the friend who inspired me to start this thread said that to develop WPF application, you need a very powerful box (minimum of 2Gb of RAM on Vista, in his words).