Developers say there's a dirty little secret about Longhorn that few Softies are discussing publicly: Longhorn won't be based on the .Net Framework. We're still expecting that the .Net Framework will ship with Longhorn – on the CD and/or "in the box" in some way. But the .Net Framework won't be at Longhorn's core, we hear. Instead, the .Net Framework will be the core for a small subset of Longhorn, specifically the Windows API Platform (WAP), which consists primarily of the "Avalon" Windows presentation system and the "Indigo" Windows communications system, our tipsters say.
News source: Microsoft Watch