A commonly used tool for source code management is Git. Git allows developers to track changes in their codebase, collaborate with other developers, and maintain version control. It supports features such as branching and merging, enabling simultaneous work on different features without conflicts. Git repositories can be hosted on platforms like GitHub and GitLab, providing additional tools for project management, code review, and bug tracking. This enhances collaborative software development, ensuring that teams can efficiently manage and integrate changes.