Everything you need to run .NET Framework applications.
The Microsoft .NET Framework 3.0 (which is formerly known as WinFX), is the new managed code programming model for Windows. It combines the power of the .NET Framework 2.0 with new technologies for building applications that have visually compelling user experiences, seamless communication across technology boundaries, and the ability to support a wide range of business processes.Microsoft .NET Framework 3.5
These new technologies are Windows Presentation Foundation, Windows Communication Foundation, Windows Workflow Foundation, and Windows CardSpace (formerly code named "Infocard"). Microsoft plans to ship .NET Framework 3.0 as part of the Windows Vista operating system. In addition, Microsoft is making these technologies available on Windows XP and Windows Server 2003. The following Community Technology Preview of .NET Framework 3.0 enables you to continue experimenting with early builds of these technologies, get acquainted with the development experience, and provide feedback to Microsoft.