Microsoft has met its self-imposed deadline to deliver Community Technology Previews (CTP) to Microsoft Developer Network subscribers. Last month Microsoft told attendees of the VSLive conference that it would deliver the bits designed for Windows XP and Windows Server 2003 before the end of March.

Avalon and Indigo are two of Longhorn's "fundamentals:" Avalon is the presentation subsystem for Longhorn and Indigo is Microsoft's next-generation platform for Web services. The third pillar of Longhorn is the core Windows infrastructure.

According to Microsoft, Avalon unifies how Windows creates, displays and manipulates documents, media, and user interfaces.

Indigo is described as ".NET technologies for building and running connected systems."

Both Avalon and Indigo were originally designed to be exclusive to the Longhorn Windows release.

Beta releases of the software are expected midway through the year.