Avalon
Charles Petzold’s MSDN article describes Microsoft’s recently revealed [“Avalon”](http://msdn.microsoft.com/longhorn/un derstanding/pillars/avalon/default.aspx) presentation system.
Message board posts were quick to note that Avalon isn’t the only framework that strikes a balance between declarative markup and imperative code. But no system that I’m aware of has the breadth and depth of functionality that Avalon will provide when it ships.