This repository provides a comprehensive continuous integration (CI) solution for ROS (Robot Operating System) projects. It automates the process of setting up a ROS environment, building code, running tests, and performing additional checks (such as code formatting, static analysis, and ABI compatibility) across multiple CI platforms including Travis CI, GitLab CI, GitHub Actions, and Bitbucket Pipelines. The system is designed to be highly configurable, supporting a wide range of ROS distributions from legacy versions to the latest releases, and isolates builds using Docker by default to ensure consistency across different environments. The architecture is modular, with clear separation of concerns: entry points for each CI system delegate to a central orchestration script (ci_main.sh), which in turn relies on specialized modules for environment setup, ROS configuration, workspace management, and various build systems (catkin_make, catkin_tools, colcon, etc.). Notable for their reusability and craftsmanship are the utility library (src/util.sh), which provides robust logging, error handling, and timing functions, and the Docker isolation layer (src/isolation/docker.sh), which handles the complexities of running CI jobs in containers including volume mounting, credential forwarding, and container lifecycle management. The project demonstrates strong engineering practices through its maintainability, active support for both ROS1 and ROS2, and adaptability to various CI systems. It has been widely adopted in the ROS community, as evidenced by its usage in numerous repositories. Technical debt is kept low through regular updates to support new ROS distributions and CI platforms, and the codebase avoids common pitfalls in shell scripting by using well-structured functions and consistent error handling.