Node.js

Node.js is a software system designed for writing highly-scalable internet applications, notably web servers.^[1] Programs are written in JavaScript, using event-driven, asynchronous I/O to minimize overhead and maximize scalability.^[2] Node.js consists of Google's V8 JavaScript engine plus several built-in libraries.

Node.js was created by Ryan Dahl starting in 2009, and its growth is sponsored by Joyent, his employer.^[3][4]

Similar environments written in other programming languages include Twisted for Python, Perl Object Environment for Perl, libevent for C and EventMachine for Ruby. Unlike most JavaScript programs, it is not executed in a web browser, but is instead a server-side JavaScript application. Node.js implements some CommonJS specifications.^[5] It provides a REPL environment for interactive testing.

Examples

This is a complete implementation of hello world as an HTTP Server in Node.js:

var http = require('http');
 
http.createServer(function (request, response) {
    response.writeHead(200, {'Content-Type': 'text/plain'});
    response.end('Hello World\n');
}).listen(8000);
 
console.log('Server running at http://127.0.0.1:8000/');

This is a simple TCP server which listens on port 7000 and echoes 'hello' upon connection:

var net = require('net');
 
net.createServer(function (stream) {
    stream.write('hello\r\n');
 
    stream.on('end', function () {
        stream.end('goodbye\r\n');
    });
 
    stream.pipe(stream);
}).listen(7000);

Community

Node.js has an active developer community primarily centered on two mailing lists, nodejs and nodejs-dev, and the IRC channel #node.js on freenode. The community gathers at NodeConf, an annual developer conference focused on Node.js.^[6]

See also

• JavaScript
• V8 (JavaScript engine)
• NPM, the Node Package Manager - the predominant package manager for Node.js. As of Node.js version 0.6.3, npm is installed automatically with Node.js.
• JSAN, the JavaScript Archive Network - a lesser used JavaScript package manager.

References

External links

• Official website
• Source Repository
• Nodejs mailing list - general discussion about Node.js
• Nodejs-dev mailing list - list for discussion of bugs and changes to Node.js itself
• The Node.js Package Manager
• How To Node tutorial web site
• Hosting compatible with Node
• How to write your own native Node.js extension
• Node.js contributor Felix Geisendörfer gives some background on Node.js on The Changelog podcast
• A thorough introduction on the PavingWays blog
• Introduction to Node.js
• Node.js and the JavaScript Age
• The Node Beginner Book, a comprehensive introduction for experienced developers that are new to Node.js
• Mixu's Node Book, a free 10-chapter book on Node.js
• A Beginner's Tutorial for Node.js, an in-depth tutorial for developers new to Node.