Yes... you read it right... it's codenamed Singularity & MS Researchers doing it from scratch...
Microsoft Research has developed a prototype of a microkernel operating system, code-named 'Singularity.' Its most surprising feature: It has nothing to do with Windows.
More
http://research.microsoft.com/os/singularity/
Microsoft Research has developed a prototype of a microkernel operating system, code-named 'Singularity.' Its most surprising feature: It has nothing to do with Windows.
More
http://research.microsoft.com/os/singularity/
