Act vs Deno

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.

Deno is an open-source JavaScript and TypeScript runtime created as a modern alternative to Node.js with built-in security, standard library, and TypeScript support. It aims to address Node.js design concerns.