TECHNOLOGY ENCYCLOPEDIA

Mozilla Firefox

Open-source web browser and nonprofit organization championing internet privacy, freedom, and accessibility

Quick Facts

Organization Type

Nonprofit Foundation + Corporation

Founded

February 28, 1998 (Project)

July 15, 2003 (Foundation)

Headquarters

San Francisco, California, USA

CEO

Laura Chambers (Interim, 2024-)

Key Products

Firefox Browser, Thunderbird, Pocket

Browser Market Share

~3.2% globally (2026)

Annual Revenue

~$593M (2022)

Rendering Engine

Gecko (Firefox), Quantum (modern)

Primary Funding

Search partnerships (Google, others)

Mozilla is a nonprofit organization and open-source software community best known for developing the Firefox web browser. Founded in 1998 as a project emerging from Netscape Communications, Mozilla has become a leading advocate for internet privacy, open standards, and digital rights while maintaining one of the few independent browser engines in an increasingly consolidated web ecosystem.

History and Origins

From Netscape to Mozilla (1998-2003)

Mozilla originated as an open-source project launched by Netscape Communications in 1998, releasing the source code of its Netscape Communicator browser suite. The name "Mozilla" was Netscape's internal codename, combining "Mosaic" (the pioneering web browser) and "Godzilla."

After AOL acquired Netscape in 1999, the Mozilla project continued as an independent open-source community. In 2003, the Mozilla Foundation was formally established as a nonprofit organization to coordinate development and promote the open web.

Firefox Launch and Growth (2004-2010)

Mozilla Firefox 1.0 launched on November 9, 2004, offering a lightweight, fast alternative to Microsoft's dominant Internet Explorer. Firefox quickly gained popularity through grassroots marketing, innovative features like tabbed browsing and pop-up blocking, and a vast library of community-developed extensions.

By 2009, Firefox had achieved approximately 30% global browser market share, representing a significant victory for open-source software and breaking Microsoft's near-monopoly on web browsing.

Chrome Competition and Evolution (2010-Present)

The launch of Google Chrome in 2008 introduced intense competition. Chrome's speed, minimalist design, and aggressive promotion led to Firefox gradually losing market share throughout the 2010s. In response, Mozilla launched major initiatives including:

  • Firefox Quantum (2017): Complete rewrite prioritizing speed and efficiency
  • Enhanced Tracking Protection (2019): Aggressive privacy features enabled by default
  • Multi-account Containers: Isolation technology preventing cross-site tracking
  • WebAssembly: Co-development of high-performance web standard

Firefox Browser

Core Features

Firefox distinguishes itself through privacy-focused features and customization capabilities:

Key Firefox Features:

Enhanced Tracking Protection

Blocks third-party trackers, cookies, cryptominers, and fingerprinters by default

Multi-Account Containers

Isolate browsing contexts to prevent tracking across different online identities

Firefox Sync

End-to-end encrypted synchronization of bookmarks, passwords, and history

Picture-in-Picture

Watch videos in floating window while browsing other content

Password Manager

Built-in encrypted password storage with breach alerts

Add-ons Ecosystem

Extensive library of browser extensions with robust API support

Reader View

Distraction-free reading mode stripping ads and clutter

Customizable Interface

Extensive theme and toolbar customization options

Technical Architecture

Firefox uses the Gecko rendering engine (branded as Quantum in modern versions), one of only three independent browser engines remaining alongside Chromium's Blink and Safari's WebKit. This independence is crucial for maintaining web standards diversity and preventing single-vendor control of the internet.

Mozilla has increasingly adopted Rust, a memory-safe systems programming language (created by Mozilla), in Firefox's codebase to improve security and performance. Components like Stylo (CSS engine) and WebRender (graphics engine) are written in Rust.

Platform Availability

  • Desktop: Windows, macOS, Linux (multiple distributions)
  • Mobile: Android (full add-ons support), iOS (using WebKit per App Store requirements)
  • Enterprise: Firefox ESR (Extended Support Release) for organizations

Market Position

Browser Market Share (2026)

BrowserDesktop ShareMobile ShareOverall Share
Google Chrome~65%~62%~63%
Safari~9%~25%~20%
Microsoft Edge~13%~1%~5%
Mozilla Firefox~6.8%~0.5%~3.2%
Others~6.2%~11.5%~8.8%

Source: StatCounter Global Stats, January 2026

While Firefox's market share has declined from its peak, it remains the fourth most-used browser globally and the most popular truly independent browser. Firefox is particularly strong among privacy-conscious users, developers, and Linux desktop users.

Privacy and Security Focus

Mozilla has positioned Firefox as the privacy-focused alternative to data-collecting browsers. Key initiatives include:

Enhanced Tracking Protection

Enabled by default since 2019, this feature blocks over 2,000 known trackers including social media trackers, cross-site tracking cookies, cryptominers, and fingerprinters. Firefox provides detailed reports showing how many trackers were blocked.

DNS over HTTPS (DoH)

Firefox pioneered widespread DoH deployment, encrypting DNS queries to prevent ISPs and network observers from tracking browsing patterns.

Total Cookie Protection

Introduced in 2021, this technology confines cookies to the site that created them, preventing cookies from being used for cross-site tracking while maintaining site functionality.

Mozilla VPN

A paid subscription service ($4.99/month) providing device-level VPN protection powered by Mullvad, available across multiple devices and operating systems.

Other Mozilla Products

Thunderbird

Open-source email client originally developed by Mozilla, now maintained by the independent MZLA Technologies Corporation. Thunderbird remains popular among power users requiring advanced email management features.

Pocket

Read-it-later service acquired by Mozilla in 2017, integrated directly into Firefox for saving articles, videos, and web pages for offline viewing. Pocket has over 20 million registered users.

Mozilla Hubs

Virtual reality social platform built on WebXR standards, allowing users to create and share virtual spaces directly in the browser without downloads or VR hardware requirements.

Common Voice

Open-source, crowd-sourced voice dataset project helping teach machines how people actually speak. The dataset includes over 30,000 hours of recorded speech in 100+ languages, available for free to developers.

Business Model and Funding

Mozilla's unique structure combines nonprofit and commercial elements:

Organizational Structure

  • Mozilla Foundation: 501(c)(3) nonprofit governing the overall mission
  • Mozilla Corporation: Wholly owned taxable subsidiary handling commercial activities

Revenue Sources

Mozilla's primary revenue (~85-90%) comes from search partnerships, primarily with Google, which pays to be Firefox's default search engine. In 2022, Mozilla reported approximately $593 million in total revenue.

Additional revenue comes from:

  • Mozilla VPN subscriptions
  • Pocket Premium subscriptions
  • Licensing and partnerships
  • Individual donations

Note: Mozilla's dependence on Google for the majority of its funding has raised questions about long-term sustainability, especially as Firefox market share declines. The search deal is renegotiated periodically, most recently renewed through 2024-2026.

Open Source and Community

Mozilla remains committed to open-source principles:

  • Source code: Firefox and most Mozilla projects released under Mozilla Public License
  • Community contributions: Thousands of volunteer developers contribute code, translations, and testing
  • MDN Web Docs: Comprehensive web development documentation maintained by Mozilla and community
  • Web standards advocacy: Active participation in W3C, IETF, and other standards bodies

Recent Developments (2024-2026)

Leadership Changes

In February 2024, Mitchell Baker stepped down as CEO after two decades of leadership, with Laura Chambers assuming the role as interim CEO while Mozilla conducts a permanent search.

AI Integration

Mozilla has begun integrating AI features into Firefox while maintaining privacy principles, including local-first AI summarization and translation tools that process data on-device rather than sending to external servers.

Layoffs and Restructuring

Mozilla has undergone several rounds of layoffs (2020, 2023) and restructuring efforts aimed at focusing resources on core products while exploring new revenue streams to reduce dependence on search partnerships.

Challenges and Future Outlook

Mozilla faces significant challenges:

  • Market share decline: Continued erosion of Firefox user base
  • Mobile weakness: Minimal presence on mobile where most browsing occurs
  • Revenue concentration: Heavy reliance on Google search payments
  • Web platform consolidation: Increasing dominance of Chromium-based browsers
  • Developer mindshare: Declining testing and optimization for Firefox

However, Mozilla remains crucial for web ecosystem health as one of the few organizations maintaining an independent browser engine and advocating for user privacy, accessibility, and open standards.

Summary:

Mozilla and Firefox represent a unique position in the modern internet landscape—a nonprofit-driven, privacy-focused alternative to commercial browsers in an ecosystem increasingly dominated by Big Tech. While facing market share challenges, Mozilla's commitment to open-source development, user privacy, and web standards independence makes it an essential counterweight to browser monoculture. The organization's future depends on diversifying revenue, regaining user trust, and demonstrating that privacy and user agency can compete in the modern web.

External Resources