Examine individual changes

'{{ infobox software | name = Node.js | logo = [[File:NodeJS.png|150px|Node.js Logo]] | screenshot = | caption = | author = Ryan Lienhart Dahl | developer = [http://github.com/ry/node/blob/master/AUTHORS Node.js Developers] | operating system = [[Mac OS X]], [[Linux]], [[Solaris (operating system)|Solaris]], [[FreeBSD]], [[OpenBSD]], [[Windows]] (older versions require [[Cygwin]]), [[webOS]] | status = Active | released = | latest release version = 0.4.10 | latest release date = {{release date|2011|07|19}} | latest preview version = 0.5.2 | latest preview date = {{release date|2011|07|22}} | programming language = [[C++]], [[JavaScript]] | genre = [[Event-driven programming|Event-driven]] [[computer network programming|networking]] | license = [[MIT License]] | website = http://nodejs.org/ }} '''Node.js''' is an [[Event-driven architecture|event-driven]] [[I/O]] [[server-side JavaScript]] environment based on [[V8 (JavaScript engine)|V8]]. It is intended for writing scalable network programs such as [[web server]]s.<ref>http://www.readwriteweb.com/hack/2011/01/wait-whats-nodejs-good-for-aga.php</ref> It was created by [[Ryan Dahl]] in 2009, and its growth is sponsored by [[Joyent]], which employs Dahl.<ref>http://mashable.com/2011/03/10/node-js/</ref> <ref name="Node.js pushes JavaScript to the server-side">{{Cite web |url= http://www.sdtimes.com/NODE_JS_PUSHES_JAVASCRIPT_TO_THE_SERVER_SIDE/By_Alex_Handy/About_JAVASCRIPT_and_NODEJS/35668 |title= Node.js pushes JavaScript to the server-side |author= Alex Handy |publisher= SDTimes |date= 2011-06-24 |accessdate= 2011-06-24}} </ref> [[Twisted (software)|Twisted]] for [[Python (programming language)|Python]], [[Perl Object Environment]] for [[Perl]], [[libevent]] for [[C]] and EventMachine for [[Ruby (programming language)|Ruby]]. Unlike most [[JavaScript]], it is not executed in a web browser, but is instead a form of [[server-side JavaScript]]. Node.js implements some [[CommonJS]] specifications.<ref>http://wiki.commonjs.org/wiki/Implementations/node.js</ref> Node.js includes a [[Read-eval-print loop|REPL]] environment for interactive testing. == Examples == [[Web server|HTTP Server]] version of [[Hello world program|hello world]] in Node.js: <source lang="javascript"> 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/'); </source> Another example with a simple [[Transmission Control Protocol|TCP]] server which listens on [[TCP and UDP port|port]] 7000 and [[echo (command)|echo]]es whatever you send it: <source lang="javascript"> 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); </source> == Modules == Node.js ships with many "core modules" compiled into the binary such as the net module, providing an asynchronous network wrapper, and other fundamental modules including Path and File System, Buffer, Timers, and the more general Stream. Third-party modules can also be used, either in the form of pre-compiled ".node" addons or in the form of plain javascript files. JavaScript Modules are implemented according to the [[CommonJS]] specification for modules,<ref>{{cite web|title=CommonJS Implementations|url=http://www.commonjs.org/impl/|accessdate=15 May 2011}}</ref> using an exports variable to give scripts access to functions and variables implemented by modules.<ref>{{cite web|last=Ryswyck|first=Jan|title=Taking Baby Steps with Node.js – CommonJS and Creating Custom Modules|url=http://elegantcode.com/2011/02/04/taking-baby-steps-with-node-js-commonjs-and-creating-custom-modules/|accessdate=15 May 2011}}</ref> Third-party modules can extend node.js or provide a level of abstraction, implementing various middleware for use in web-applications, such as popular frameworks connect and express. Although modules can be installed as simple files, they are usually installed using Node Package Manager (npm) which can assist in building, installing and updating modules with dependency-handling. Furthermore, modules that are not installed in Node's default module directory will require a relative path name to be found. The [https://github.com/joyent/node/wiki/modules Node.js wiki] hosts a list of various third-party modules available. == Community == There is a very active Node.js developer community primarily centered around two mailing lists, [http://groups.google.com/group/nodejs nodejs] and [http://groups.google.com/group/nodejs-dev nodejs-dev], and the [[IRC]] channel #node.js on [[freenode]]. The community gathers at an [http://nodeconf.com/ NodeConf], an annual developer conference focused on Node.js.<ref>http://www.readwriteweb.com/hack/2011/04/nodeconf-schedule-announced.php</ref> == See also == {{Portal|Free software}} * [[JavaScript]] * [[V8 (JavaScript engine)]] * [[Node Package Manager|NPM]], the Node Package Manager - the predominant package manager for Node.js. * [[JSAN]], the JavaScript Archive Network - a lesser used JavaScript package manager. == References == {{reflist}} == External links == *{{Official website|http://nodejs.org}} *[https://github.com/joyent/node Source Repository] *[http://groups.google.com/group/nodejs Nodejs mailing list] - general discussion about Node.js *[http://groups.google.com/group/nodejs-dev Nodejs-dev mailing list] - list for discussion of bugs and changes to Node.js itself *[http://npmjs.org/ The Node.js Package Manager] *[http://howtonode.org/ How To Node tutorial web site] *[http://syskall.com/how-to-write-your-own-native-nodejs-extension How to write your own native Node.js extension] *[http://thechangelog.com/post/501053444/episode-0-2-0-node-js-with-felix-geisendorfer Node.js contributor Felix Geisendörfer gives some background on Node.js on The Changelog podcast] *[http://www.pavingways.com/nodejs-node-is-important-introduction_1288.html A thorough introduction on the PavingWays blog] *[http://net.tutsplus.com/tutorials/javascript-ajax/this-time-youll-learn-node-js/ Introduction to Node.js] *[http://gigaom.com/cloud/node-js-and-the-javascript-age/ Node.js and the JavaScript Age] *[http://www.nodebeginner.org The Node Beginner Book], a comprehensive introduction for experienced developers that are new to Node.js {{Compu-lang-stub}} [[Category:JavaScript libraries]] [[de:Node.js]] [[es:Node.js]] [[fa:نود.جی‌اس]] [[fr:Node.js]] [[ko:Node.js]] [[it:Node.js]] [[ja:Node.js]] [[ru:Node.js]]'