Windows Azure – Free Cloud OS
What is it? It is a completely free Developers Operating System for use exclusively with Cloud server farms. This is the first try by Microsoft to do something completely different. The idea is to get people to play and work with the product. That way in the future this can be sold for a profit.
Makes sense to me, develop a good OS so it will be adopted.
Source: http://www.microsoft.com/azure/default.mspx
Offical Annoucement: http://www.microsoft.com/presspass/press/2008/oct08/10-27PDCDay1PR.mspx
Channel 9 Video: http://channel9.msdn.com/posts/Charles/Manuvir-Das-Introducing-Windows-Azure/