Node.js

Node.js

Original author(s)	Ryan Lienhart Dahl
Developer(s)	Node.js Developers
Stable release	0.6.11 / February 17, 2012 (2012-02-17)
Preview release	0.7.5 / February 23, 2012 (2012-02-23)
Development status	Active
Written in	C++, JavaScript
Operating system	Mac OS X, Linux, Solaris, FreeBSD, OpenBSD, Windows (older versions require Cygwin), webOS
Type	Event-driven networking
License	MIT License
Website	nodejs.org

Node.js is a software system designed for writing scalable internet applications, notably web servers. Programs are written in JavaScript, using event-driven, asynchronous I/O to minimize overhead and maximize scalability. 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.

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. It provides a REPL environment for interactive testing.

Node.js was selected by InfoWorld for the Technology of the Year Award in 2012.

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://localhost: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 a 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.

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.

External links

• Official website
• The Node.js Package Manager