Gecko (Software)

Gecko
गेको

Developer(s)	Mozilla Foundation, Mozilla Corporation, Adobe Systems, and other contributors
Stable release	125 /  ()
Written in	C++, JavaScript, Rust
Type	Browser engine
License	MPL 2.0
Website	developer.mozilla.org/en-US/docs/Glossary/Gecko

Gecko (stylized as ɢecko) is a browser engine created by Mozilla. It powers the Firefox web browser, the Thunderbird email client, and various other applications.

Gecko is built to adhere to open Internet standards and is utilized by different software to render web pages and, in some instances, the user interface of applications themselves (by processing XUL). It provides a comprehensive programming API, making it well-suited for a diverse range of functions in Internet-connected applications, including web browsers, content display, and client/server interactions.

Gecko, a software written in C++, JavaScript, and since 2016, Rust, is open-source and licensed under the Mozilla Public License version 2. It is maintained and supported by Mozilla for use on various operating systems including Android, Linux, macOS, and Windows. The software can be utilized freely in accordance with the terms of its license.

History

Netscape started creating a new layout engine called Gecko in 1997 after buying DigitalStyle. The previous Netscape rendering engine was slow, not standard compliant, had limited dynamic HTML support, and lacked features like incremental reflow. The new engine was developed alongside the old one, with plans to add it to Netscape Communicator when ready. It was expected that at least one more version of Netscape would come out with the old engine before switching to Gecko.

The new layout engine's code was made open-source after the Mozilla project started in 1998. It was first called Raptor, but the name was changed to NGLayout (Next generation layout) because of trademark issues. Netscape later named it Gecko , and although Mozilla Organization initially kept using NGLayout (as Gecko was a Netscape trademark), the name Gecko became the preferred branding.

In October 1998, Netscape announced that its upcoming browser would use a new layout engine called Gecko (previously known as NGLayout), instead of the old one. This decision was welcomed by web standards advocates, but it was unpopular with Netscape developers, who were given only six months to rewrite large parts of the application. As a result, most of the work done for Netscape Communicator 5.0, including improvements to the old layout engine, had to be abandoned. The first Netscape release to incorporate Gecko was Netscape 6, which was released in November 2000. The name Netscape 5 was never used.

As the development of Gecko progressed, other applications and software integrators started to use it as well. America Online, which had acquired Netscape by this time, eventually adopted Gecko for use in CompuServe 7.0 and AOL for Mac OS X. These products had previously used Internet Explorer. However, Gecko was not used in the main Microsoft Windows AOL client, except for a few beta versions.

In July 2003, AOL laid off the remaining Gecko developers, and the newly formed Mozilla Foundation became the primary steward of Gecko's development. Today, Gecko is developed by employees of the Mozilla Corporation, contributors from other companies, and volunteers.

During the Netscape era, a combination of technical and management decisions led to Gecko becoming bloated. As a result, in 2001, Apple chose to fork KHTML, rather than use Gecko, to create the WebKit engine for its Safari browser. However, by 2008, Mozilla had addressed some of the bloat issues, leading to significant performance improvements for Gecko.

In 2016, Mozilla announced Quantum, an ongoing project to build the next-generation web engine for Firefox. This included numerous improvements to Gecko, drawing from the experimental Servo project. Firefox 57, also known as "Firefox Quantum," released in 2017, was the first version to incorporate major components from the Quantum/Servo projects, such as increased performance in CSS and GPU rendering.

In 2018, Mozilla announced GeckoView, a software library that allows Gecko to be embedded in other applications, including their next-generation mobile products. Firefox Focus 7.0, released the same year, was the first version to use GeckoView, with improved page loading performance. Firefox Reality and the ongoing Firefox Preview project for Android also utilize GeckoView. The first stable release of Firefox for Android 79, known as "Firefox Daylight," was powered by the GeckoView engine.