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Brendan Eich

Summary

Brendan Eich is an American software engineer who created JavaScript. At Netscape he built its first version, code-named Mocha, in May 1995, in ten days by his own account, and Netscape and Sun Microsystems announced the name JavaScript on December 4, 1995. He co-founded the mozilla.org project in 1998, became chief technical officer of the Mozilla Corporation in 2005, and in 2015 co-founded Brave Software, maker of the Brave browser.

Web Building Encyclopedia · People · Last reviewed October 22, 2026 · 8 min read

Early life and career before Netscape

Brendan Eich holds a bachelor of science degree in mathematics and computer science from Santa Clara University and a master of science in computer science from the University of Illinois.1 The history of JavaScript that he co-wrote for the ACM’s History of Programming Languages conference (HOPL) says he completed the master’s degree, at Urbana-Champaign, in 1985.2

After his master’s degree he went straight to Silicon Graphics, Inc. (SGI), where he worked mainly on the Unix kernel and networking layers. The kernel is the core of an operating system. In 1992 he left SGI to join MicroUnity, a startup developing video media processors.2

At both companies he wrote small special-purpose languages for kernel and networking work, and at MicroUnity he also worked on the GCC compiler.2 A compiler is a program that turns source code written by people into instructions a computer can run.

Creating JavaScript at Netscape, 1995 and 1996

Eich joined Netscape Communications on April 3, 1995.2 Netscape made the Netscape Navigator web browser. Eich has written that he was recruited on the promise that he could put Scheme, an existing programming language, into the browser.3

That plan changed when Netscape and Sun Microsystems agreed to put Sun’s Java language into the browser. On May 23, 1995, Netscape announced that it intended to license Java. According to the HOPL history, the only approach senior managers at Netscape and Sun considered workable was a small scripting language to complement Java.2 Eich wrote in 2008 that upper engineering management required the new language to look like Java.3

According to the HOPL history, he built the first prototype, code-named Mocha, in ten contiguous days in May 1995. A prototype is a first working version built to prove an idea. The code name was proposed by Netscape co-founder Marc Andreessen.2 Eich later described the result as a cross of the C language and Self, a language built around prototype objects, and said he was glad he had chosen first-class functions from Scheme: functions that can be stored and passed around like any other value.3

The public first saw the language in September 1995, under the name LiveScript, in a beta (test) release of Navigator 2.0. Netscape and Sun announced the name JavaScript in a joint press release on December 4, 1995, and the finished Navigator 2.0 shipped with JavaScript 1.0 in March 1996.2 The JavaScript entry covers the language itself, from those first versions to the present.

Rewriting the engine: SpiderMonkey

After Navigator 3.0 was released in August 1996, Eich spent two weeks working from home, where he redesigned and reimplemented the core of the JavaScript engine, the part of the browser that runs scripts.2 The HOPL history calls the result “a faster, more reliable, and more flexible execution engine.” When Eich returned to the office, the new engine replaced Mocha.2

Chris Houck named the new engine SpiderMonkey, and SpiderMonkey became the name of the JavaScript part of later Netscape and Mozilla browsers.2 The name is still in use. As of October 2026, Mozilla describes SpiderMonkey as its JavaScript and WebAssembly engine, used in Firefox, Servo and other projects, and written in C++, Rust and JavaScript.4

Eich also changed how the language behaved. The first JavaScript 1.2 beta came out in December 1996. For that version he removed most of the automatic type conversions from the == comparison operator, because users had found the original rules surprising and confusing. Under the new rule, two values of different basic types, such as a number and a string, were not equal.2

Standardizing the language: Ecma and ECMAScript

A standard is a public document that defines how a technology must behave, so that different companies can build versions that work the same way. In September 1996, the Co-ordinating Committee of the standards organization Ecma considered a Netscape request to start a JavaScript standardization activity, and Netscape formally applied to join Ecma as an associate member.2

The organizing meeting of the new committee, TC39 (Technical Committee 39), took place on November 21 and 22, 1996, at Netscape’s offices in Mountain View, California. Eich is on its attendee list for Netscape. Ecma’s General Assembly approved the creation of TC39 in December 1996.2

The first edition of the standard, ECMA-262, says the work started in November 1996 and that the Ecma General Assembly adopted it in June 1997. It names JavaScript from Netscape and JScript from Microsoft as the best-known versions of the language.5 The standard calls the language ECMAScript, and its first edition was edited by Guy Steele.2 The second and third editions followed in August 1998 and December 1999.6

ES4 and Harmony

By the late 2000s Eich, then at Mozilla, was arguing for a fourth edition known as ES4. In an April 2008 post he wrote that the web, and JavaScript with it, had to keep evolving, and gave that as the reason for ES4.3

The plan changed that summer. On August 13, 2008, Eich wrote to the es-discuss mailing list that TC39, meeting in Oslo at the end of July, had agreed to finish a smaller update called ES3.1 first, then work together on a more modest successor he called Harmony. He wrote that ES4’s packages, namespaces and early binding were “off the table for good.”7

No fourth edition was ever published. The fifth edition is dated December 2009 and the sixth June 2015. As of October 2026, the newest is the 17th edition, ECMAScript 2026, dated June 2026.6

Mozilla, 1998 to 2014

On January 22, 1998, Netscape announced plans to make the source code of its next Communicator browser suite available free on the internet. On February 23, 1998, it announced mozilla.org, a dedicated team and website to support development of that code.8 Source code is the human-readable form of a program. Mozilla says the Mozilla project was created in 1998 with the release of the Netscape browser suite source code.9

Eich has described mozilla.org as a project he co-founded, and Mozilla has said he was involved in its development from the original idea in 1998.310 An archived mozilla.org staff page says he was responsible for architecture and the technical direction of Mozilla. His duties included authorizing module owners, the people in charge of each part of the code, and writing the project’s roadmap.11

Mozilla’s archived history lists four development roadmaps and a Mozilla 1.0 manifesto written by Eich between October 1998 and April 2003.8 His roadmap of October 26, 1998 told the project to stop working on the old layout code and build on NGLayout, a new layout engine. A layout engine is the part of a browser that turns HTML and CSS into what appears on screen. The roadmap said the features content developers wanted most, including correct CSS and a Level 1 DOM, had been hard to add to the old code.12

The roadmap of April 2, 2003, which Eich wrote with David Hyatt, moved development toward new standalone applications, which the archived version names as Firefox and Thunderbird. It kept the older all-in-one suite on sustaining maintenance, including security updates.813 The Mozilla project created the Mozilla Foundation, an independent nonprofit, in 2003, and Firefox 1.0 was released in 2004.9

On August 3, 2005, the Mozilla Foundation formed a wholly owned subsidiary, the Mozilla Corporation, to make products such as Firefox and Thunderbird. The announcement said Eich, “a co-founder and long-time technical leader of the Mozilla project,” would become the corporation’s chief technical officer, and listed him on the Foundation’s board of directors.14

Mozilla appointed Eich CEO on March 24, 2014, moving him from the role of chief technology officer.10 On April 3, 2014, Mozilla announced that he had stepped down as CEO, and Eich wrote the same day that he had resigned and was leaving Mozilla.1516

WebAssembly and Brave, 2015 onward

On June 17, 2015, Eich announced WebAssembly on his blog. He described it as “a new binary syntax for low-level safe code,” able at first to express the same programs as asm.js, a strict subset of JavaScript. He wrote that the work had so far been a joint effort among Google, Microsoft, Mozilla and a few others.17 A binary format is compact code meant for machines to read, not text meant for people.

On December 5, 2019, the W3C made the WebAssembly core specification a W3C Recommendation, its term for a finished standard, and called WebAssembly the fourth language for the web that lets code run in the browser.18

Brave

Eich co-founded Brave Software with Brian Bondy in 2015. As of October 2026, the company lists him as founder and CEO and gives its headquarters as San Francisco.19 Its Brave browser has a feature called Shields, on by default for every site, that blocks third-party ads, trackers and cross-site cookies and protects against fingerprinting. Brave can also warn when a site shows signs of phishing.20 Fingerprinting means identifying a visitor from details of their device and browser instead of a cookie.

Brave’s company timeline lists its first desktop beta in 2016 and its first desktop release built on Chromium in 2018. On desktop and Android, the browser is a fork of the open-source Chromium engine; on iOS it uses Apple’s WebKit.19 A fork is a separate copy of a project’s code that is developed on its own. Brave 1.0 was released on November 13, 2019, and the company reported 10.4 million monthly active users at the end of that month.21

In 2017 Brave raised $35 million through a sale of the Basic Attention Token (BAT), a cryptocurrency token that users who opt in to Brave’s private ads can earn. In 2021 it bought Tailcat, whose technology and team became Brave Search, a search engine with its own web index.19 As of September 30, 2026, Brave reported 128.3 million monthly active users and 54.6 million daily active users.22

Where his work is documented

The fullest account of Eich’s work on JavaScript is the history he wrote with Allen Wirfs-Brock, “JavaScript: The First 20 Years,” for the fourth HOPL conference. It was published on June 12, 2020, and the authors’ corrected version of March 2021 is free to read under a Creative Commons Attribution license.2 The paper lists Eich’s affiliation as Brave Software, Inc.2

Eich has also written about his work on his own site, brendaneich.com. His posts include the April 2008 account of the language’s origins, written in the week of mozilla.org’s tenth anniversary, and the June 2015 announcement of WebAssembly.317 The early mozilla.org roadmaps he wrote remain online in Mozilla’s archive.8

Timeline

  1. Brave 1.0 is released21
  2. Eich announces WebAssembly on his blog17
  3. Eich and Brian Bondy co-found Brave Software19
  4. Eich resigns as Mozilla CEO and leaves Mozilla15
  5. Mozilla appoints Eich CEO10
  6. Eich reports the TC39 agreement on ES3.1 and Harmony7
  7. Eich is named CTO of the new Mozilla Corporation14
  8. Eich and David Hyatt's roadmap moves Mozilla to standalone applications8
  9. Eich's roadmap moves mozilla.org to the NGLayout engine12
  10. Netscape announces mozilla.org8
  11. Ecma adopts the first edition of ECMA-262 (ECMAScript)5
  12. Eich attends TC39's organizing meeting at Netscape2
  13. Netscape and Sun announce the name JavaScript2
  14. Eich builds the Mocha prototype, in ten days by his account2
  15. Eich joins Netscape Communications2

What it means for your website

The language Eich started, the browser engine he rebuilt and the browser company he runs all affect how a small business site behaves for its visitors.

  • Your site runs JavaScript. As of October 22, 2026, W3Techs finds JavaScript on 98.9% of websites.23 Builders, themes and each plugin can add their own scripts. Ask your developer, or check your builder’s settings, which third-party scripts load on every page, and remove the ones you no longer use. Our guide to how a website works explains what runs in the browser and what runs on the server.
  • Test with Brave’s Shields on. Brave reported 128.3 million monthly active users as of September 30, 2026.22 Shields blocks third-party ads, trackers and cross-site cookies by default, and replaces some problem scripts with stripped-down versions.20 Open your contact form, booking widget and checkout in Brave and make sure each one still works.
  • Expect gaps in tracking. Because Shields blocks trackers by default, some visits and conversions may not reach your analytics or ad reports.20 Our page on websites and Google Ads explains how conversion tracking works.
  • Keep the essentials in the page itself. A Brave user can turn Shields off for one site, but only by choosing to.20 Put your phone number, address and main service text in the page’s own HTML, not only inside a script or an embedded widget.
  • Ask about language versions. Ecma went from the 6th edition of ECMAScript in June 2015 to the 17th in June 2026.6 If a developer uses the newest features, ask them to confirm that the browsers your visitors use support them.

See also

References

  1. The State of JavaScript (speaker biography of Brendan Eich). Strange Loop 2012. 2012. accessed October 22, 2026.
  2. JavaScript: The First 20 Years (Allen Wirfs-Brock and Brendan Eich), Proc. ACM Program. Lang. 4, HOPL, Article 77, authors' corrected version. Zenodo. 2020-06-12. accessed October 22, 2026.
  3. Popularity. Brendan Eich, brendaneich.com. 2008-04-03. accessed October 22, 2026.
  4. SpiderMonkey JavaScript/WebAssembly Engine. Mozilla, spidermonkey.dev. accessed October 22, 2026.
  5. Standard ECMA-262, 1st edition: ECMAScript, A general purpose, cross-platform programming language. Ecma International. 1997-06. accessed October 22, 2026.
  6. ECMA-262: ECMAScript language specification. Ecma International. accessed October 22, 2026.
  7. ECMAScript Harmony (Brendan Eich, es-discuss mailing list). esdiscuss.org. 2008-08-13. accessed October 22, 2026.
  8. mozilla.org history (archived). Mozilla. accessed October 22, 2026.
  9. History of the Mozilla Project. Mozilla. accessed October 22, 2026.
  10. Mozilla Leadership Changes. Mozilla Blog. 2014-03-24. accessed October 22, 2026.
  11. mozilla.org staff (archived). Mozilla. 2006-11-04. accessed October 22, 2026.
  12. Development Roadmap (Brendan Eich). mozilla.org (archived). 1998-10-26. accessed October 22, 2026.
  13. Mozilla Development Roadmap (Brendan Eich and David Hyatt). mozilla.org (archived). 2003-04-02. accessed October 22, 2026.
  14. Mozilla Foundation Forms New Organization to Further the Creation of Free, Open Source Internet Software, Including the Award-Winning Mozilla Firefox Browser. Mozilla press release. 2005-08-03. accessed October 22, 2026.
  15. Brendan Eich Steps Down as Mozilla CEO. Mitchell Baker, Mozilla Blog. 2014-04-03. accessed October 22, 2026.
  16. The Next Mission. Brendan Eich, brendaneich.com. 2014-04-03. accessed October 22, 2026.
  17. From ASM.JS to WebAssembly. Brendan Eich, brendaneich.com. 2015-06-17. accessed October 22, 2026.
  18. World Wide Web Consortium (W3C) brings a new language to the Web as WebAssembly becomes a W3C Recommendation. W3C press release. 2019-12-05. accessed October 22, 2026.
  19. About Brave. Brave Software. accessed October 22, 2026.
  20. Brave Shields. Brave Software. accessed October 22, 2026.
  21. Brave Passes 10 Million Monthly Active Users, and Sees 19% Growth since 1.0 Launch. Brave Blog. 2019-12-05. accessed October 22, 2026.
  22. Brave transparency report. Brave Software. 2026-09-30. accessed October 22, 2026.
  23. Usage statistics of client-side programming languages for websites. W3Techs. 2026-10-22. accessed October 22, 2026.

Web Building Encyclopedia. First published October 22, 2026. Last reviewed October 22, 2026. Every fact on this page is linked to a source we opened. Spotted an error? Write to [email protected].