Singularity

Singularity is an open-source operating system developed by Microsoft Research that focuses on process isolation, strong security, and reliability. It uses a microkernel architecture with software-isolated processes that communicate exclusively through message passing over contract-based channels. Processes run as manifest-based programs defined by static manifest files that describe resources, capabilities, and dependencies. The Singularity kernel provides primitive facilities through an application binary interface and handles memory management and scheduling for isolated processes.