The document describes the Singularity project, which aims to redesign operating system architectures and software stacks to improve dependability and trustworthiness. The key architectural features of Singularity systems are software-isolated processes (SIPs) for isolation, contract-based channels for communication between SIPs, and manifest-based programs (MBPs) for verification of system properties. SIPs provide lightweight process isolation through type safety instead of hardware protection. Communication between SIPs occurs via channels defined by message contracts. MBPs specify the code and behavior of processes.