node.js

File:Ryan Dahl.jpg

File:Node.JS Mascot.svg

Node.js was initially written by Ryan Dahl in 2009,{{cite web |date=2016-09-11 |title=About Node.js, and why you should add Node.js to your skill set? |url=http://blog.training.com/2016/09/about-nodejs-and-why-you-should-add.html |access-date=23 October 2016 |website=Training.com |ref=training.com |archive-date=1 April 2017 |archive-url=https://web.archive.org/web/20170401061100/http://blog.training.com/2016/09/about-nodejs-and-why-you-should-add.html |url-status=dead }} about 13 years after the introduction of the first server-side JavaScript environment, Netscape's LiveWire Pro Web.{{Cite news |last=Staff |first=CNET News |date=1996-10-15 |title=Netscape opens intranet attack |language=en |work=CNET |url=https://www.cnet.com/news/netscape-opens-intranet-attack/ |access-date=2017-04-20}} The initial release supported only Linux and Mac OS X. Its development and maintenance was led by Dahl and later sponsored by Joyent.{{cite web |url= https://groups.google.com/forum/#!topic/nodejs/lWo0MbHZ6Tc|title= Joyent and Node|author= Ryan Dahl|publisher= Google Groups|date= 2010-11-09|access-date = 2015-02-05}}

Dahl criticized the limited capability of Apache HTTP Server to handle many (10,000+) concurrent connections, as well as the dominant programming paradigm of sequential programming, in which applications could block entire processes or cause the creation of multiple execution stacks for simultaneous connections.{{cite web |last=Garbar |first=Dzmitry |title=PHP 7 vs Node.js? They Can Be Partners, Not Competitors For a Developer! |url=https://belitsoft.com/php-development-services/php7-vs-nodejs |access-date=21 December 2016 |website=belitsoft.com}}

Dahl demonstrated the project at the inaugural European JSConf on November 8, 2009.[https://books.google.com/books?id=KGt-FxUEj48C&dq=nodejs&pg=PT24 Sams Teach Yourself Node.js in 24 Hours], Sams Publishing, 05-Sep-2012{{Cite web |last=Ubl |first=Malte |date=2009-09-09 |title=JSConf.eu 2009, Berlin, Germany |url=https://www.jsconf.eu/2009/speaker/speakers_selected.html |access-date=2009-09-09 |website=www.jsconf.eu}}{{Cite web|url=https://www.youtube.com/watch?v=ztspvPYybIY |archive-url=https://ghostarchive.org/varchive/youtube/20211215/ztspvPYybIY |archive-date=2021-12-15 |url-status=live|title=Ryan Dahl: Original Node.js presentation|date=8 June 2012 |via=www.youtube.com}}{{cbignore}} Node.js combined Google's V8 JavaScript engine, an event loop, and a low-level I/O API.[https://books.google.com/books?id=ZH6bpbcrlvYC&q=nodejs Professional Node.js: Building JavaScript Based Scalable Software], John Wiley & Sons, 01-Oct-2012

In January 2010, a package manager was introduced for the Node.js environment called npm.{{cite web |url=https://github.com/npm/npm/releases?after=v0.1.1 |title=Earliest releases of npm |website=GitHub |access-date = 27 July 2016}} The package manager allows programmers to publish and share Node.js packages, along with the accompanying source code, and is designed to simplify the installation, update and uninstallation of packages.

In June 2011, Microsoft and Joyent implemented a native Windows version of Node.js.{{cite web |last=Ryandahl |date=2011-06-23 |title=Porting Node to Windows With Microsoft's Help |url=https://nodejs.org/en/blog/uncategorized/porting-node-to-windows-with-microsofts-help/ |access-date=17 April 2016 |website=nodejs.org}} The first Node.js build supporting Windows was released in July 2011.

In January 2012, Dahl yielded management of the project to npm creator Isaac Schlueter.{{cite web|url=http://groups.google.com/forum/#!topic/nodejs/hfajgpvGTLY|title=New gatekeeper|last=Dahl|first=Ryan|access-date = 26 October 2013}} In January 2014, Schlueter announced that Timothy J. Fontaine would lead the project.{{cite web|url=https://nodejs.org/en/blog/uncategorized/tj-fontaine-new-node-lead/|title=The Next Phase of Node.js|last=Schlueter|first= Isaac|date=15 January 2014|access-date = 21 January 2014}}

{{anchor|Io.js}}In December 2014, Fedor Indutny created io.js, a fork of Node.js created because of dissatisfaction with Joyent's governance as an open-governance alternative with a separate technical committee. The goal was to enable a structure that would be more receptive to community input, including the updating of io.js with the latest Google V8 JavaScript engine releases, diverging from Node.js's approach at that time.[http://www.infoworld.com/article/2855057/application-development/why-iojs-decided-to-fork-nodejs.html Q&A: Why io.js decided to fork Node.js], InfoWorld Tech Watch

The Node.js Foundation, formed to reconcile Node.js and io.js under a unified banner, was announced in February 2015.{{cite web|url=https://www.linuxfoundation.org/news-media/announcements/2015/06/nodejs-foundation-advances-community-collaboration-announces-new|title=Node.js Foundation Advances Community Collaboration, Announces New Members and Ratified Technical Governance|access-date = 4 July 2015|url-status=dead|archive-url=https://web.archive.org/web/20150624075643/http://www.linuxfoundation.org/news-media/announcements/2015/06/nodejs-foundation-advances-community-collaboration-announces-new|archive-date=24 June 2015}} The merger was realized in September 2015 with Node.js v0.12 and io.js v3.3 combining into Node v4.0.{{cite web |date=2015-09-14 |title=Node.js Foundation Combines Node.js and io.js Into Single Codebase in New Release |url=https://nodejs.org/en/blog/announcements/foundation-v4-announce/ |access-date=28 January 2016 |website=nodejs.org}} This merge brought V8 ES6 features into Node.js and started a long-term support release cycle.{{cite web |date=19 May 2015 |title=io.js and Node.js merge |url=https://medium.com/node-js-javascript/io-js-week-of-may-15th-9ada45bd8a28 |access-date=27 June 2015 |website=medium.com}} By 2016, the io.js website recommended returning to Node.js and announced no further io.js releases, effectively ending the fork and solidifying the merger's success.[https://iojs.org/en/ Io.js, JavaScript I/O], "io.js has merged with the Node.js project again. There won't be any further io.js releases. All of the features in io.js are available in Node.js v4 and above."

In 2019, the JS Foundation and Node.js Foundation merged to form the OpenJS Foundation.

The Node.js logo features a green hexagon with overlapping bands to represent the cross-platform nature of the runtime.{{cite web |title=Brand Guide |url=https://nodejs.org/static/documents/foundation-visual-guidelines.pdf |website=Node.js |publisher=OpenJS Foundation |access-date=22 March 2024}} The Rocket Turtle was chosen as the official Node.js mascot in February 2024 following a design contest.{{cite web |title=Node.JS on X: "Meet Rocket Turtle there are many ways 👋" |url=https://twitter.com/nodejs/status/1759953849849167878 |access-date=22 March 2024}}

Node.js allows the creation of web servers and networking tools using JavaScript and a collection of "modules" that handle various core functionalities.[https://books.google.com/books?id=G1y_5kpmatUC&q=nodejs Smashing Node.js: JavaScript Everywhere], John Wiley & Sons, 14-Aug-2012 Modules are provided for file system I/O, networking (DNS, HTTP, TCP, TLS/SSL or UDP), binary data (buffers), cryptography functions, data streams and other core functions.[https://nodejs.org/api/ Modules], Nodejs Website Node.js's modules use an API designed to reduce the complexity of writing server applications.[https://books.google.com/books?id=dPaoCwAAQBAJ&q=nodejs Node.js Essentials], Packt Publishing, 10-Nov-2015

JavaScript is the only language that Node.js supports natively, but many compile-to-JS languages are available.{{Cite web|url=https://github.com/jashkenas/coffeescript/wiki/list-of-languages-that-compile-to-js|title=List of languages that compile to JS|website=Github}} As a result, Node.js applications can be written in CoffeeScript,{{cite book |url=https://books.google.com/books?id=Oda-MgEACAAJ&q=nodejs |title=CoffeeScript on Node.js |publisher=O'Reilly Media, Inc. |date=15 April 2013 |access-date = 17 May 2015|isbn=9781449316846 }} Dart, TypeScript, ClojureScript and others.

Node.js is primarily used to build network programs such as web servers.[https://books.google.com/books?id=KZQQAlhTOBgC&q=nodejs Node.js for PHP Developers], O'Reilly Media, Inc., 2013 The most significant difference between Node.js and PHP is that most functions in PHP block until completion (commands execute only after previous commands finish), while Node.js functions are non-blocking (commands execute concurrently and use callbacks to signal completion or failure), thus opening up new attack surfaces that are inherently absent in most web server applications.

Node.js is officially supported by Linux, {{nowrap|macOS}} and Microsoft Windows 8.1 and Server 2012 (and later), with Tier 2 support for SmartOS and IBM AIX and experimental support for FreeBSD. OpenBSD also works, and LTS versions are available for IBM i (AS/400).{{Cite web |last=Foundation |first=Node js |title=Installing Node.js via package manager |url=https://nodejs.org/en/download/package-manager/ |access-date=2019-05-19 |website=Node.js |language=en}} The source code may also be built on similar operating systems that are not officially supported, such as NonStop OS{{cite web |title=bomBora - Node.js for NonStop |url=http://infrasoft.com.au/bomBora.html |access-date=14 August 2015 |website=infrasoft.com.au |publisher=Infrasoft |archive-date=11 March 2018 |archive-url=https://web.archive.org/web/20180311040354/http://infrasoft.com.au/bomBora.html |url-status=dead }} and Unix servers.

Node.js enables development of fast web servers in JavaScript using event-driven programming. Developers can create scalable servers without using threading by using a simplified model that uses callbacks to signal the completion of a task.{{Page needed|date=November 2023|reason=Event-driven programming generally doesn't rely on threads and is often more complex; unclear what was meant in the source.}} Node.js connects the ease of a scripting language (JavaScript) with the power of Unix network programming.

Node.js was built on top of Google's V8 JavaScript engine since it was open-sourced under the BSD license, and it contains comprehensive support for fundamental protocols such as HTTP, DNS and TCP. JavaScript's existing popularity made Node.js accessible to the web-development community.

There are thousands of open-source libraries for Node.js, most of which are hosted on the npm website. Multiple developer conferences and events are held that support the Node.js community, including NodeConf, Node Interactive, and Node Summit, as well as a number of regional events.

The open-source community has developed web frameworks to accelerate the development of applications. Such frameworks include Express.js, Socket.IO, Sails.js, Next.js and Meteor.[https://books.google.com/books?id=5eGRAwAAQBAJ&q=nodejs Express.js Guide: The Comprehensive Book on Express.js], Azat Mardan, 28-May-2014 Various packages have also been created for interfacing with other languages or runtime environments such as Microsoft .NET.[http://www.techrepublic.com/article/edge-js-bridges-the-gap-between-node-js-and-net/ Edge.js bridges the gap between Node.js and .NET], TechRepublic, Tony Patton, 1 July 2014

Modern desktop IDEs provide editing and debugging features specifically for Node.js applications. Such IDEs include Atom, Brackets, JetBrains WebStorm,[https://www.jetbrains.com/webstorm/help/node-js.html Node.js], WebStorm supports integration with the Node.js runtime environment, WebStorm Help[https://www.jetbrains.com/webstorm/help/running-and-debugging-node-js.html Running and Debugging Node.js], WebStorm Help Microsoft Visual Studio (with Node.js Tools for Visual Studio,{{cite web |title=Node.js Tools for Visual Studio |url=https://www.visualstudio.com/en-us/features/node-js-vs.aspx |access-date=1 Feb 2016 |website=microsoft.com}} or TypeScript with Node definitions[https://github.com/soywiz/typescript-node-definitions soywiz/typescript-node-definitions TypeScript's typings for some popular node.js modules], GitHub[https://github.com/DefinitelyTyped/DefinitelyTyped DefinitelyTyped], GitHub{{Cite web|url=http://definitelytyped.org/|archiveurl=https://web.archive.org/web/20160203083254/http://definitelytyped.org/|url-status=dead|title=The repository for high quality TypeScript type definitions|archivedate=3 February 2016|website=definitelytyped.org}}[https://www.typescriptlang.org/Samples#ImageBoard ImageBoard, A Node.js + Express + MongoDB application built using TypeScript on the server] {{Webarchive|url=https://web.archive.org/web/20190518111659/http://www.typescriptlang.org/samples/#ImageBoard |date=18 May 2019 }}, TypeScript Samples), NetBeans,{{cite web |last=Krill |first=Paul |date=2015-11-10 |title=Node.js takes center stage in NetBeans 8.1 |url=http://www.infoworld.com/article/3003414/java/nodejs-takes-center-stage-in-netbeans-81.html |access-date=2015-11-10 |website=infoworld.com |publisher=InfoWorld}} Nodeclipse Enide Studio{{usurped|1=[https://web.archive.org/web/20120508061750/http://www.nodeclipse.org/ Nodeclipse, Enide -- Node.JS development in Eclipse]}}, Nodeclipse Website (Eclipse-based) and Visual Studio Code.[https://channel9.msdn.com/Blogs/cloud-with-a-silver-lining/hello-visual-studio-code-nodejs Hello Visual Studio Code (with NodeJS)], Channel 9, Microsoft

[https://code.visualstudio.com/Docs/runtimes/nodejs Node.js Applications with VS Code], Visual Studio Code

Some online IDEs also support Node.js, such as Codeanywhere, Eclipse Che, Cloud9 IDE and the visual flow editor in Node-RED.

Node.js is supported across a number of cloud-hosting platforms such as Jelastic, Google Cloud Platform, AWS Elastic Beanstalk, Azure Web Apps and Joyent.

Platinum (34.x 2030)

New major releases of Node.js are cut from the GitHub main branch every six months. Even-numbered versions are cut in April and odd-numbered versions are cut in October. When a new odd version is released, the previous even version undergoes transition to Long Term Support (LTS), which gives that version 12 months of active support from the date it is designated LTS. After these 12 months expire, an LTS release receives an additional 18 months of maintenance support. An active version receives non-breaking backports of changes a few weeks after they land in the current release. A maintenance release receives only critical fixes and documentation updates.{{Cite web|url=https://github.com/nodejs/Release|title=nodejs/Release|website=GitHub|language=en|access-date=2018-05-03}} The LTS Working Group manages strategy and policy in collaboration with the Technical Steering Committee of the Node.js Foundation.

Node.js is a JavaScript runtime environment that processes incoming requests in a loop, called the event loop.

Node.js uses libuv under the hood to handle asynchronous events. Libuv is an abstraction layer for network and file system functionality on both Windows and POSIX-based systems such as Linux, macOS, OSS on NonStop, and Unix. Node.js relies on nghttp2 for HTTP support. As of version 20, Node.js uses the ada library which provides up-to-date WHATWG URL compliance. As of version 19.5, Node.js uses the simdutf library for fast Unicode validation and transcoding. As of version 21.3, Node.js uses the simdjson library for fast JSON parsing.

Node.js operates on a single-thread event loop, using non-blocking I/O calls, allowing it to support tens of thousands of concurrent connections without incurring the cost of thread context switching.{{cite web|url=http://blog.caustik.com/2012/08/19/node-js-w1m-concurrent-connections/|title=Node.js w/1M concurrent connections!|work=caustik's blog|date=19 August 2012}} The design of sharing a single thread among all the requests that use the observer pattern is intended for building highly concurrent applications, where any function performing I/O must use a callback. To accommodate the single-threaded event loop, Node.js uses the libuv library—which, in turn, uses a fixed-sized thread pool that handles some of the non-blocking asynchronous I/O operations.

A thread pool handles the execution of parallel tasks in Node.js. The main thread function call posts tasks to the shared task queue, which threads in the thread pool pull and execute. Inherently non-blocking system functions such as networking translate to kernel-side non-blocking sockets, while inherently blocking system functions such as file I/O run in a blocking way on their own threads. When a thread in the thread pool completes a task, it informs the main thread of this, which in turn, wakes up and executes the registered callback.

A downside of this single-threaded approach is that Node.js does not allow vertical scaling by increasing the number of CPU cores of the machine it is running on without using an additional module, such as cluster,{{cite web |title=Node.js's cluster module |url=https://nodejs.org/api/cluster.html |access-date=19 October 2017 |website=nodejs.org}} StrongLoop Process Manager,{{Cite web|url=http://strong-pm.io/|title=StrongLoop Process Manager|website=strong-pm.io}} or pm2.{{cite web|url=https://github.com/Unitech/pm2|title=GitHub - Unitech/pm2: Production process manager for Node.js applications with a built-in load balancer|work=GitHub|date=12 June 2021}} However, developers can increase the default number of threads in the libuv thread pool. The server operating system (OS) is likely to distribute these threads across multiple cores.{{cite web|url=http://www.future-processing.pl/blog/on-problems-with-threads-in-node-js/|title=On problems with threads in node.js - Future Processing|author=Aleksander Kasiuk|date=22 April 2015}} Another problem is that long-lasting computations and other CPU-bound tasks freeze the entire event-loop until completion.{{citation needed|date=March 2017}}

{{Main|V8 (JavaScript engine)}}

V8 is the JavaScript execution engine which was initially built for Google Chrome. It was then open-sourced by Google in 2008. Written in C++, V8 compiles JavaScript source code to native machine code at runtime. As of 2016, it also includes Ignition, a bytecode interpreter.

npm is the pre-installed package manager for the Node.js server platform. It installs Node.js programs from the npm registry, organizing the installation and management of third-party Node.js programs.

Node.js registers with the operating system so the OS notifies it of asynchronous I/O events such as new connections. Within the Node.js runtime, events trigger callbacks and each connection is handled as a small heap allocation. Traditionally, relatively heavyweight OS processes or threads handled each connection. Node.js uses an event loop for concurrent I/O, instead of processes or threads.[https://nodejs.org/about/ About Node.js], Node.js Website In contrast to other event-driven servers,{{which|date=November 2023}} Node.js's event loop does not need to be called explicitly. Instead, callbacks are defined, and the server automatically enters the event loop at the end of the callback definition. Node.js exits the event loop when there are no further callbacks to be performed.

Node.js supports WebAssembly and as of Node 14 has experimental support of WASI, the WebAssembly System Interface.

{{See also|Foreign function interface}}

Node.js provides a way to create "add-ons" via a C-based API called N-API, which can be used to produce loadable (importable) .node modules from source code written in C/C++.{{Cite web|title=C++ addons {{!}} Node.js v14.12.0 Documentation|url=https://nodejs.org/api/addons.html|access-date=2020-09-26|website=nodejs.org}} The modules can be directly loaded into memory and executed from within JS environment as simple CommonJS modules. The implementation of the N-API relies on internal C/C++ Node.js and V8 objects requiring users to import (#include) Node.js specific headers into their native source code.

As the Node.js API is subject to breaking changes at a binary level, modules have to be built and shipped against specific Node.js versions to work properly. To address the issue, third parties have introduced open-sourced С/С++ wrappers on top of the API that partially alleviate the problem. They simplify interfaces, but as a side effect they may also introduce complexity which maintainers have to deal with. Even though the core functionality of Node.js resides in a JavaScript built-in library, modules written in C++ can be used to enhance capabilities and to improve performance of applications.

In order to produce such modules one needs to have an appropriate C++ compiler and necessary headers (the latter are typically shipped with Node.js itself), e.g., gcc, clang or MSVC++.

The N-API is similar to Java Native Interface.

{{Main|OpenJS Foundation}}

In 2015, various branches of the greater Node.js community began working under the vendor-neutral Node.js Foundation. The stated purpose of the organization "is to enable widespread adoption and help accelerate development of Node.js and other related modules through an open governance model that encourages participation, technical contribution, and a framework for long-term stewardship by an ecosystem invested in Node.js' success."{{Cite web|url=https://nodejs.org/en/foundation/|title=Node.js Foundation {{!}} Node.js|last=Foundation|first=Node.js|website=nodejs.org|language=en|access-date=2017-03-08}}

The Node.js Foundation Technical Steering Committee (TSC) is the technical governing body of the Node.js Foundation. The TSC is responsible for the core Node.js repo as well as dependent and adjacent projects. Generally the TSC delegates the administration of these projects to working groups or committees.{{Cite web|url=https://github.com/nodejs/TSC|title=nodejs/TSC|website=GitHub|language=en|access-date=2017-03-08}} The LTS group that manages long term supported releases is one such group. Other current groups include Website, Streams, Build, Diagnostics, i18n, Evangelism, Docker, Addon API, Benchmarking, Post-mortem, Intl, Documentation, and Testing.{{Cite web|url=https://nodejs.org/en/about/working-groups/|title=Working Groups {{!}} Node.js|last=Foundation|first=Node.js|website=nodejs.org|language=en|access-date=2017-03-08|archive-date=27 February 2017|archive-url=https://web.archive.org/web/20170227070535/https://nodejs.org/en/about/working-groups/|url-status=dead}}

In August 2017, a third of the TSC members resigned due to a dispute related to the project's code of conduct.Whittaker, Zack, [https://www.zdnet.com/article/after-governance-breakdown-node-js-leaders-fight-for-its-survival/?loc=newsletter_large_thumb_related&ftag=TREc64629f&bhid=24465828771686428160302951310435/ After governance breakdown, Node.js leaders fight for its survival], ZDNet, 25 August 2017

{{Reflist|30em}}

• {{citation | title = Up and Running with Node.js | date = April 2012 | last1 = Hughes-Croucher | last2 = Wilson | first1 = Tom | first2 = Mike | publisher = O'Reilly Media | isbn = 978-1-4493-9858-3 }}
• {{citation | title = Sams Teach Yourself Node.js in 24 Hours | date = September 2012 | last1 = Ornbo | first1 = George | publisher = SAMS Publishing | isbn = 978-0-672-33595-2 }}
• {{citation | title = Professional Node.js | date = October 2012 | url = http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1118185463,descCd-authorInfo.html | last1 = Teixeira | first1 = Pedro | publisher = John Wiley & Sons | isbn = 978-1-118-22754-1 }}
• {{cite podcast | url = http://twit.tv/show/floss-weekly/237 | title =Episode 237: Node.js | website = twit.tv/show/floss-weekly | publisher = TWiT.tv | host = Randal L. Schwartz and Aaron Newcomb | date = 9 January 2013 | time = 1:08:13 | access-date = 9 January 2013 }}
• {{citation | title = Node.js Recipes: A Problem-Solution Approach | date = October 2013 | last1 = Gackenheimer | first1 = Cory | publisher = Apress | isbn = 978-1-4302-6058-5}}

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