Way back when, as Microsoft struggled to deliver a follow up to Windows XP, its Longhorn vision sat on top of what it called “the three pillars of Longhorn”: a database-powered object file system called WinFS, a new set of communication tools based on web services code-named Indigo, and a new presentation layer based on a graphical description language code-named Avalon. Only Indigo and Avalon survived to be part of Windows Vista, as .NET’s Windows Communication Framework and Windows Presentation Framework (WPF).
