Main Function is a tiny Node.js utility that wraps an async entry‑point, converting thrown errors into appropriate console output and process exit codes. It lets developers define a `main` function that can return a numeric code or throw a `ProgramError` (for graceful exits) or any other error (logged with a stack and exits with code 1). Ideal for CLI authors who want a clean, standardized way to handle errors and exit statuses in JavaScript/TypeScript scripts.