Development of the layout engine now known as Gecko began at
Netscape in 1997, following the company's purchase of
DigitalStyle. The existing Netscape rendering engine, originally written for
Netscape Navigator 1.0 and upgraded through the years, was slow, did not comply well with W3C standards, had limited support for
dynamic HTML and lacked features such as incremental reflow (when the layout engine rearranges elements on the screen as new data is downloaded and added to the page). The new layout engine was developed in parallel with the old, with the intention being to integrate it into Netscape Communicator when it was mature and stable. At least one more major revision of Netscape was expected to be released with the old layout engine before the switch. After the launch of the Mozilla project in early 1998, the new layout engine code was released under an open-source license. Originally unveiled as
Raptor, the name had to be changed to
NGLayout (next generation layout) due to
trademark problems. Netscape later rebranded NGLayout as
Gecko. While
Mozilla Organization (the forerunner of the
Mozilla Foundation) initially continued to use the NGLayout name (Gecko was a Netscape trademark), eventually the Gecko branding won out. In October 1998, Netscape announced that its next browser would use Gecko (which was still called NGLayout at the time) rather than the old layout engine, requiring large parts of the application to be rewritten. While this decision was popular with web standards advocates, it was largely unpopular with Netscape developers, who were unhappy with the six months given for the rewrite. In the Netscape era, a combination of poor technical and management decisions resulted in Gecko
software bloat. Thus in 2001
Apple chose to fork
KHTML, not Gecko, to create the
WebKit engine for its
Safari browser.
Quantum In October 2016, Mozilla announced
Quantum, an ongoing project encompassing several
software development efforts to "build the next-generation web engine for
Firefox users". It included numerous improvements to Gecko, taken from the experimental
Servo project. Firefox 57, also known as "Firefox Quantum", first shipped in November 2017 and was the initial version with major components from the Quantum/Servo projects enabled. These include increased performance in the
CSS and
GPU rendering components. Additional components will be merged from Servo to Gecko incrementally in future versions. is the initial version introduced GeckoView, with increased performance in median page loading. Firefox Reality was also built with GeckoView. Firefox for Android 79, also known as "Firefox Daylight", first shipping in August 2020, is the first stable release of that with major components powered by GeckoView engine. ==Standards support==