Act vs Babel

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.

Babel is an open-source JavaScript compiler that transforms modern ECMAScript syntax into backward-compatible versions for older browsers and environments. It supports plugins for JSX, TypeScript, and experimental JavaScript proposals.