In my ongoing effort to link to every SDK in the world, here's the WinFX Beta 1 SDK for your coding pleasure.
Microsoft® WinFX ™ Software Development Kit for Microsoft® Pre-Release Windows Operating System Code-Named "Longhorn", Beta 1 Web SetupHere is a direct link to the ISO, if you prefer to install from a disc. (Thanks to Norm Diamond for pointing out that I was linking to an earier version.)
The WinFX SDK contains documentation, samples and tools designed to help you develop managed applications and libraries using WinFX, which is the set of next-generation managed APIs provided by Microsoft. This release includes documentation about using the .NET Framework 2.0, the Windows Presentation Foundation (formerly code named Avalon), and the Windows Communications Foundation (formerly code named Indigo).