Concourse CI is an open-source continuous integration and continuous delivery (CI/CD) tool. It is designed to be expressive, versatile, and safe, making it suitable for projects of any complexity. Concourse employs a simple mechanics of resources, tasks, and jobs to automate the CI/CD process efficiently. It allows users to configure their pipelines as code, specifying input resources and defining tasks to be executed when changes occur. The pipelines can be visualized in the web UI, providing a clear overview of the project's progress. Concourse emphasizes reproducibility and debuggability, running builds in containers to ensure a clean environment each time. Local iteration is made easy with the "fly execute" command, allowing users to test builds with local changes without interrupting the pipeline. Moreover, Concourse can integrate with various external systems through resource types, offering flexibility and adaptability. The tool is built in the open, with an RFC process and governance model that welcomes contributions from anyone. Concourse can be downloaded for Linux, macOS, and Windows operating systems. Overall, Concourse CI is a powerful and customizable CI/CD tool that provides an intuitive and efficient automation platform for developers.