Microsoft has made beta versions of its Longhorn's Avalon and Indigo technologies available to the general public for download. When this software was first made available, only paying subscribers of the Microsoft Developer's Network (MSDN) could get it.
Indigo and Avalon are the codenames for two of three core technologies that will be available in Longhorn when it ships in 2006. These technologies are only available for Windows XP and Windows Server 2003.
If you want to know more about these, technologies here are excerpts from the Microsoft site that briefly describe them:
"Indigo is the codename for Microsofts unified programming model for building connected systems. It extends the .NET Framework 2.0 with additional APIs for building secure, reliable, transacted Web services that interoperate with non-Microsoft platforms and integrate with existing investments." ... "Avalon is the code name for Microsoft's unified presentation subsystem for Windows. It consists of a display engine and a managed-code framework. Avalon unifies how Windows creates, displays, and manipulates documents, media, and user interface."
To download this software go to the following web page.