The document discusses Swarm, an Agile development tool that allows teams to collaborate and review code. Swarm aims to help software teams ship quality software faster through flexible reviews, code conversations and sharing, support for multiple sites, and combining the power of Perforce and Git. It operates based on principles of swarming where individuals move in the same direction and remain close to avoid collisions, similar to how code review helps teams move in the same direction, remain connected and avoid issues. The tool offers extensibility and allows users to choose their own workflow for code reviews.