Act vs Homebrew

act is an open-source command-line tool that runs GitHub Actions workflows locally using Docker containers. It reads workflow files from .github/workflows/ and executes them with environment variables and filesystem configurations matching GitHub's hosted runners. The tool enables fast local feedback on workflow changes without requiring commits and pushes to a remote repository.

Homebrew is a developer-utilities tool that package manager for macos and linux that simplifies installing command-line tools and applications. It is open source software.