Cider: is the Visual Studio tool that will help design Avalon Forms (Windows Presentation Foundation) through the Visual Studio IDE.
It is revealed that "Cider" (though it sounds like an alcoholic drink) will resemble the Windows forms designer.
An overview of the concept is uncovered in the latest MSDN-TV episode by Mark Boulter and Mike Harsh, dated 20th October 2005. They also take a quick look at "Sparkle" in this episode. Check it out here:
http://msdn.microsoft.com/msdntv/episode.aspx?xml=episodes/en/20051020CiderMB/manifest.xml