For some time, rumors have suggested that Microsoft engineers have been working on a non-Windows operating system. ZDNet's Mary Jo Foley reports that there have been two significant developments in the story.
First, unnamed sources say that the project has been moved into the Unified Operating System group, making it more likely that the project will eventually see the light of day.
Second, a Midori team member named Joe Duffy has blogged about M#, the language used to build the OS. Sources say it is an extension of C#. The blog suggests the language could eventually become open source.