Midori is a componentized non-Windows operating system which is architected from the ground up by Microsoft. Midori is an offshoot of Microsoft Research’s singularity operating system, the tools and libraries of which are completely managed code. Midori is designed to run directly on native hardware (x86, x64 and ARM), be hosted on the Windows Hyper-V hypervisor, or even be hosted by a Windows process. 
Singularity guiding philosophy is simplicity over richness.
The Singularity system consists of three key architectural features:
- software-isolated processes
- contract-based channels
- manifest-based programs
Software-isolated processes provide an environment for program execution protected from external interference.
Contract-based channels enable fast, verifiable message-based communication between processes.
Manifest- based programs define the code that runs within software-isolated processes and specify its verifiable behavioral properties.
If a new OS is to succeed windows then a clear path to migrate the applications should be well defined. The use of distributed application, web 2.0, SOA , are in need in many cases only for devices that are capable of running a web browser only. Nevertheless an OS that is stable and able of handling effectively threads, processes and concurrency problems is more than welcome.
 David Worthington (2008). Microsoft’s plans for post-Windows OS revealed. [Online] Available here
 Galen C. Hunt and James R. Larus (2007). Singularity: Rethinking the Software Stack [Online] Available here