Singularity is a Microsoft Research project started in 2003 to build a highly-dependable OS in which the kernel, device drivers and applications are all written in managed code.
Singularity is a research project in Microsoft Research that started with the question: what would a software platform look like if it was designed from scratch with the primary goal of dependability? Singularity is working to answer this question by building on advances in programming languages and tools to develop a new system architecture and operating system (named Singularity), with the aim of producing a more robust and dependable software platform. Singularity demonstrates the practicality of new technologies and architectural decisions, which should lead to the construction of more robust and dependable systems.
From research.microsoft.com and wikipedia. Hope this makes a little light.
