Node.js is an open-source, cross-platform, JavaScript runtime environment. It executes JavaScript code outside of a browser.

npm(1) -- a JavaScript package manager

npx(1) -- execute npm package binaries

ECMA-262, the ECMAScript® Language Specification.

The Express philosophy is to provide small, robust tooling for HTTP servers, making it a great solution for single page applications, web sites, hybrids, or public HTTP APIs.