Microsoft .NET Framework 3.0 has been released to manufacturing ... this provides advances for building rich, interactive client applications (Windows Presentation Foundation), communication and workflow (Windows Communication Foundation and Windows Workflow Foundation) and online identity management (Windows CardSpace).

You can download the .NET Framework 3.0 components here:

• .NET Framework 3.0 Runtime Components
• Windows SDK for Vista and the .NET Framework 3.0
• Visual Studio 2005 Extensions for .NET Framework 3.0 (Windows Workflow Foundation)
• Visual Studio 2005 Extensions for .NET Framework 3.0 (WCF & WPF), November 2006 CTP

Note, if you are using Windows Vista the .NET Framework 3.0 Runtime Components are installed by default. The Readme for the released version of the .NET Framework 3.0 is available here.