The set of core libraries like express (fka connect) + dependencies is the stdlib. It was developed in early node.js days as part of CommonJS, which was an initiative for a portable/modular server-side JavaScript runtime with many implementations besides node.js (RingoJS, Narwhal, Helma, TeaJs/v8cgi). The existence of a community-driven lib effort, the portable nature of JavaScript, and the existence of choice was the entire reason I even looked into node.js.