60 Fun Facts About JavaScript

Who created JavaScript in 1995?

He went on to co-found the Firefox maker and later the Brave browser company.

At which company was JavaScript created, for its Navigator browser?

Its founders had built Mosaic, the first popular graphical browser, and wanted Navigator to do more than display static pages.

What was the language called when it first shipped in a Navigator beta in September 1995?

The name switched to JavaScript for the official release that December, riding the hype around Sun's new language.

JavaScript's creator was originally recruited to embed which existing language in the browser?

Management then decided the new language should look like Java instead, which is why the syntax owes so little to Lisp.

In December 1995, which company jointly announced JavaScript with the browser maker in a press release?

Its creator has called the JavaScript name a marketing ploy to piggyback on a hotter language's popularity.

Netscape management wanted the syntax of Brendan Eich's new language to resemble which language?

Despite the shared name and syntax, the two languages differ greatly in design.

Under what name is the language standardised by Ecma International's TC39 committee?

The first edition was adopted in June 1997, seven months after the language was submitted for standardisation.

The core language standard is published under which document number?

ECMA-404 is JSON, ECMA-334 is C#, and ECMA-119 is the ISO 9660 CD-ROM file system.

Ecma International, the standards body behind the language, is based in which city?

The name stopped being an acronym for European Computer Manufacturers Association in 1994.

What did Internet Explorer 3.0 call its own implementation of the language in 1996?

The two implementations differed enough to spawn years of 'best viewed in' badges on websites.

Which term did Jesse James Garrett coin in 2005 for loading data in the background without a full page reload?

The XMLHttpRequest idea behind it came from the Outlook Web Access team in 1998.

Chrome shipped in 2008 with which JavaScript engine, faster than anything else at the time?

It was named after the car engine, and its lead developer was Lars Bak.

Which engine, the first ever written for the language, has powered Firefox since 2004?

Its JIT compilers have been called TraceMonkey, JägerMonkey, IonMonkey and WarpMonkey.

Apple's WebKit began in 2001 as a fork of KHTML and which KDE JavaScript engine?

Lisa Melton started the WebKit project inside Apple on 25 June 2001, choosing the KDE code because it was small and clean.

Node.js was created in 2009 by whom?

He was frustrated that Apache could not handle 10,000-plus concurrent connections, and demoed Node at the first European JSConf.

Node's creator later co-created which runtime, announced in a 2018 talk about his regrets?

It is written in Rust after an early start in Go, and its name is an anagram of Node.

The Bun runtime, unlike Node, uses which JavaScript engine?

Jarred Sumner released Bun in September 2021, and Anthropic acquired it in December 2025.

Which package manager was introduced for Node.js in January 2010?

Officially it is a recursive backronym for 'npm is not an acronym', not 'Node Package Manager'.

In March 2016, the unpublishing of which tiny package broke Babel, webpack and thousands of builds?

It was pulled after a naming dispute between its author Azer Koçulu and the messaging company Kik.

In December 2014 Fedor Indutny forked Node.js over its governance. What was the fork called?

The fork tracked the latest V8 releases and was later merged back, with governance passing to what became the OpenJS Foundation.

In January 2012, Node's founder handed management of the project to the creator of npm. Who was that?

Joyent sponsored the project in those years and built the native Windows version with Microsoft in 2011.

Who created jQuery in January 2006?

He wrote it at BarCamp NYC, influenced by Dean Edwards' cssQuery, and it is still the most deployed JavaScript library by a wide margin.

React was created by Jordan Walke, a software engineer at which company?

It first ran on the News Feed in 2011 and on Instagram in 2012 before being open-sourced.

React was officially open-sourced at a JavaScript conference in which year?

React Native followed in 2015, announced at React Conf that February.

React Hooks such as useState and useEffect arrived in which version?

They let function components hold state and side effects, and cannot be used inside classes.

Vue.js was created by which developer after he had worked at Google with AngularJS?

Vue was publicly announced in February 2014 and is pronounced like 'view'.

Svelte, the framework that compiles components away at build time, was created by whom?

Its predecessor was his earlier Ractive.js, and version 1 of Svelte arrived on 29 November 2016.

Next.js, the React framework with server-side rendering, was created by which company?

Guillermo Rauch wrote the original version, released on GitHub on 25 October 2016.

Which engineer originally developed AngularJS in 2009 for an online JSON storage service?

Google eventually stopped updating it on 1 January 2022, having replaced it with the ground-up rewrite Angular.

Ember.js got its name in December 2011 when which framework's 2.0 version was renamed?

Yehuda Katz, its creator, later sat on TC39, the committee that steers the language.

CoffeeScript, Backbone.js and Underscore.js were all created by which developer?

His first CoffeeScript commit, on 13 December 2009, was labelled 'initial commit of the mystery language'.

What does the D3 in D3.js stand for?

It succeeded Mike Bostock's earlier Protovis framework, with version 2.0.0 landing in August 2011.

Which developer, known online as Mr.doob, first released the 3D library Three.js on GitHub in 2010?

He had originally written it in ActionScript for Flash before porting it in 2009.

Electron, the desktop framework behind VS Code, Slack and Discord, was originally built for which editor?

It was called Atom Shell at first, and pairs a Chromium renderer with a Node.js back end.

Which creator of Turbo Pascal and C# led Microsoft's TypeScript project?

TypeScript shipped publicly as version 0.8 in October 2012; in 2025 Microsoft announced a port of the compiler to Go for version 7.

By August 2025, which language had overtaken JavaScript as the most used on GitHub?

It transpiles to JavaScript, so in a sense the winner and the loser are the same code.

Who specified the JSON format and, with Chip Morningstar, sent the first JSON message in April 2001?

He also wrote JavaScript: The Good Parts, JSLint and JSMin, and coined 'truthy' and 'falsy'.

Why did JSON's designer say he deliberately left comments out of the format?

He said the practice 'would have destroyed interoperability'; JSON also forbids trailing commas.

Which portable binary format, a W3C recommendation since 2019, lets C, C++ and Rust run in browsers?

It won ACM SIGPLAN's Programming Languages Software Award in 2021.

asm.js, the strict JavaScript subset that paved the way for Wasm, was started at which organisation?

Firefox 22 was the first browser to ship asm.js-specific optimisations.

Which company took over the 'JavaScript' US trademark in 2009?

The mark was issued to Sun in 1997 and passed to Oracle with its 2009 takeover; a 2024 letter with over 14,000 signatories, including the language's creator, asked for it to be freed.

Which JavaScript interpreter shipped inside JDK 8, alongside the jjs command-line tool?

It was later dropped in favour of GraalJS, which lets JavaScript create and call Java objects.

Block-scoped let and const were added in which edition of the language?

Before that, var gave only function scoping, and developers faked blocks with immediately-invoked function expressions.

The abandoned fourth edition of the standard was to be based on ActionScript 3 from which company?

Without Internet Explorer's maker on board the effort was mothballed, and ES5 arrived instead in December 2009.

Since ES6, how often is a new edition of the language standard finalised?

The draft is maintained openly on GitHub and each edition is a snapshot of it.

Which JavaScript value is not equal to itself?

It stands for Not a Number, is itself of type number, and behaves exactly as the IEEE 754 standard says it should.

Which of these values is truthy in JavaScript?

Only 0, -0, null, NaN, undefined and the empty string are falsy; every non-empty string and every object is truthy.

Template literals with embedded ${expression} syntax are delimited by which character?

They can also span multiple lines, which ordinary quoted strings cannot.

How are ordinary JavaScript numbers represented in memory?

Infinity is a number too, and so is its negative.

Which primitive type, written with a trailing n, holds integers of any size?

It exists because ordinary numbers can only safely store integers between Number.MIN_SAFE_INTEGER and Number.MAX_SAFE_INTEGER.

Implementing which built-in key makes an object iterable with for...of and the spread operator?

Symbols arrived in ES6; each one is guaranteed unique, which makes them useful for hidden properties.

A JavaScript Date object stores a millisecond count from midnight UT on which date?

Its range is about plus or minus 100 million days, which comfortably covers recorded history.

Automatic insertion of which punctuation mark lets JavaScript programmers omit statement terminators?

The rules occasionally bite, which is why many style guides still insist on typing them.

The with statement is not allowed once a script opts into what?

The same mode also refuses to let you assign to an undeclared variable, which used to silently create a global.

A JavaScript identifier may begin with a letter, an underscore, or which other character?

jQuery's whole API hangs off that rule, in the form of $().

JavaScript's object model does inheritance through what, rather than classes?

The idea was popularised by the Self language of David Ungar and Randall Smith; ES6 classes are sugar over the same mechanism.

JavaScript is single-threaded. What is the mechanism that processes its message queue one at a time?

It is described as 'run to completion' because each message is fully handled before the next is considered.

Roughly what share of websites used JavaScript for client-side behaviour in 2025?

Over 80% of them also loaded a third-party library or framework, with jQuery still far ahead.

Node.js was first demonstrated in November 2009 at the inaugural European edition of which conference?

He said the project was a reaction to Apache's trouble with more than 10,000 concurrent connections.

A July 2008 conference in which city brought the feuding JavaScript factions together, leading to ECMAScript 5?

The resulting agreement in early 2009 combined the rival efforts; ES5 was released that December.