Churn PHP is a tool that helps identify potentially risky or high-maintenance pieces of code in a PHP codebase. It does this by analyzing how often classes or functions are modified (churn rate) and how complex they are (cyclomatic complexity). The main goal is to find parts of the code that change frequently and are difficult to maintain, indicating that they might benefit from refactoring or closer attention.
In essence, Churn PHP helps developers manage technical debt by flagging problematic areas that could potentially cause issues in the future. It integrates well with Git repositories and can be run as part of a CI/CD pipeline.