Microsoft told attendees of the VSLive conference in San Francisco that it will deliver a Community Technology Preview (CTP) of Longhorn's "Indigo" communications subsystem by the end of March.

The CTP source code will follow and contain aspects of the WinFX programming model and, when released, will join Longhorn's Avalon presentation system in the public domain in the lead up to a complete Longhorn beta.

Like Avalon, Indigo is one of Longhorn's "fundamentals." Current builds are designed for Windows XP and Windows Server 2003 to give developers the opportunity to voice their opinion about corresponding technologies prior to Longhorn's arrival.

The fundamentals of Longhorn include: Avalon for graphics, Indigo as a second-generation Web services platform, and the core Windows infrastructure.

Microsoft Watch, which reported from VSLive, said keynote presenter Eric Rudder, Microsoft's senior vice president of servers and tools, also indicated that a new build of Visual Studio 2005 is on deck to ship out with the March CTPs. However, Rudder but did not specify whether or not the bits will be the long-awaited Beta 2 "Whidbey" milestone release.