Microsoft Research is focusing on construction of dependable systems through innovation in several areas like systems, languages, and tools via its new free Operating System Singularity. Its a research project which crossed 30k downloads in its project life time till date. Singularity is being built as a research OS prototype by extending programming languages, and by developing some new techniques and tools for specifying and verifying program behavior.
You can check out the Architecture of Singularity in the pic here:
Singualrity is on CodePlex and its Research Development Kit (RDK) 2.0 can be downloaded for academic non-commercial use. An ISO is available on CodePlex here. This project includes source code, build tools, test suites, design notes, and other background materials.