Node.js is a JavaScript runtime environment used by companies like eBay, Yahoo, PayPal, and LinkedIn in production. It is event-driven, non-blocking, and built on Google's V8 JavaScript engine, making it well-suited for real-time applications that require scalability and I/O intensive operations. Additional tools like NPM and no-SQL databases like MongoDB and CouchDB aid development by providing reusable components, version/dependency management, and JSON support.