Firefox

Yeah, that's what I get on mobile.

checks desktop

Looks like the same is also true of desktop, so it's just that they changed it over time.

kagis

Here's a history:

https://en.wikipedia.org/wiki/The_Book_of_Mozilla

And the beast shall be made legion. Its numbers shall be increased a thousand thousand fold. The din of a million keyboards like unto a great storm shall cover the earth, and the followers of Mammon shall tremble.

— from The Book of Mozilla, 3:31 (Red Letter Edition)

The chapter and verse number 3:31 refers to March 31, 1998, when Netscape released its source code.

The Book of Mozilla page has the following comment in its HTML source about this passage:[7]

<!-- 31st March 1998: the Netscape Navigator source code was released -->
<!-- The source code is made available to the legion of thousands of coders of the open source community, that will fight against the followers of Mammon (Microsoft Internet Explorer). -->

Again, the "beast" is Netscape. The text probably refers to Netscape's hope that, by opening its source, they could attract a "legion" of developers all across the world, who would help improve the software (with the "din of a million keyboards"). The "legion" is actually a reference to the biblical quote Mark 5:9 in the King James Version (KJV) bible ("And he asked him, What is thy name? And he answered, saying, My name is Legion: for we are many."), since The Book of Mozilla is presented as a sort of "computer bible" with prophecies. "Mammon" refers to Microsoft, whose Internet Explorer browser was Netscape's chief competition. The word "mammon," in various Semitic languages, is related to money and riches; it appears in English translations of the Bible, and is sometimes used as the name of a demon of avarice.

And so at last the beast fell and the unbelievers rejoiced. But all was not lost, for from the ash rose a great bird. The bird gazed down upon the unbelievers and cast fire and thunder upon them. For the beast had been reborn with its strength renewed, and the followers of Mammon cowered in horror.

— from The Book of Mozilla, 7:15

In the HTML source of Book of Mozilla page, this verse is accompanied by the following annotation:[7]

<!-- 15th July 2003: AOL closed its Netscape division and the Mozilla foundation was created -->
<!-- The beast died (AOL closed its Netscape division) but immediately rose from its ashes (the creation of the Mozilla foundation and the Firebird browser, although the name was later changed to Firefox). -->

The "beast" falling refers to Netscape being closed down by its now parent company AOL. The "great bird" that rises from the ash is the Mozilla Foundation, which was established to continue Mozilla development. The bird rises from the ash like a phoenix – a reference to the original name of the Mozilla Firefox browser (known as Firebird at the time this verse was written). The bird casts down "fire" and "thunder" on the "unbelievers", which is a direct reference to the Mozilla Firebird (now Firefox) and Mozilla Thunderbird products, which became the main focus of Mozilla development a few months before the events of July 15. The fact that the beast has been "reborn" indicates that the spirit of Netscape will live on through the Foundation (which is made up mostly of ex-Netscape employees) and its strength has been "renewed" as the foundation is less reliant on AOL (who many feel neglected Netscape). Again, "Mammon" is Microsoft, Mozilla's main commercial competitor.

And thus the Creator looked upon the beast reborn and saw that it was good.

— from The Book of Mozilla, 8:20

The 8:20 chapter and verse notation refers to August 20, 2006, when the first internal email was sent mentioning the possibility of developing the next Netscape Navigator in house.

Mammon slept. And the beast reborn spread over the earth and its numbers grew legion. And they proclaimed the times and sacrificed crops unto the fire, with the cunning of foxes. And they built a new world in their own image as promised by the sacred words, and spoke of the beast with their children. Mammon awoke, and lo! it was naught but a follower.

— from The Book of Mozilla, 11:9 (10th Edition)

<!-- 9th November 2004: Firefox 1.0 is officially released -->
<!-- The worldwide support of Firefox fans leads to its success, illustrating the power of community-based open source projects. -->

"Mammon" is again Internet Explorer, which "slept" for the 5 years between releases (between Internet Explorer 6 and 7). The "beast reborn" refers to Firefox, which gained supporters who self-organized through Spread Firefox and undertook publicity for the browser, taking out an advertisement in The New York Times and making a crop circle shaped like the Firefox logo. The "cunning of foxes" is a direct reference to Firefox's name. The "new world" refers to modern, standards-based dynamic websites and open source applications. The latter half of the passage links to the Mozilla Manifesto and the about:Mozilla newsletter. The last part, starting with "Mammon awoke," speaks of the release of Internet Explorer 7 and with "it was naught but a follower" describes it as a follower, copying several of the functions in Firefox that Internet Explorer previously lacked.[10] Additionally, "10th edition" is an allusion to the Mozilla Foundation's 10th anniversary, which occurred during the Firefox 3 development cycle.[12]

The twins of Mammon quarrelled. Their warring plunged the world into a new darkness, and the beast abhorred the darkness. So it began to move swiftly, and grew more powerful, and went forth and multiplied. And the beasts brought fire and light to the darkness.

— from The Book of Mozilla, 15:1

The "twins of Mammon" refers to Apple and Google, whose mobile operating systems, respectively iOS and Android, have taken a duopoly of the mobile OS market. The "new darkness" refers to the closed nature of traditional app stores. The beast moving "swiftly" refers to the new rapid release cycle of Firefox. The phrase "went forth and multiplied" refers to "Firefox becoming multiple things"[13] through Firefox for Android and Firefox OS. The verse number 15:1 refers to the code freeze of Firefox OS 1.0 (January 15, 2013).[14]

The Beast adopted new raiment and studied the ways of Time and Space and Light and the Flow of energy through the Universe. From its studies, the Beast fashioned new structures from oxidised metal and proclaimed their glories. And the Beast's followers rejoiced, finding renewed purpose in these teachings.

— from The Book of Mozilla, 11:14

It refers to the major changes that culminated in the Firefox 57 release with the Quantum project. "Time and Space" refer to Quantum itself, while "Flow" refers to the Quantum Flow project,[16] "new raiment" and "Light" refer to the UI refresh known as the Photon project.[17] The Quantum Project contained the first major piece of code taken from Servo,[18] the layout engine written in Rust, to which "oxidised metal" is a reference. The 11:14 chapter and verse notation refers to November 14, 2017, the day Firefox 57 was released.

The Beast continued its studies with renewed Focus, building great Reference works and contemplating new Realities. The Beast brought forth its followers and acolytes to create a renewed smaller form of itself and, through Mischievous means, sent it out across the world.

— from The Book of Mozilla, 6:27

<!-- 27th June 2019: Firefox Preview is made available for testing by early adopters -->
<!-- Firefox Focus, Reference Browser, and Firefox Reality all use the new GeckoView as does Firefox for Android which was rebuilt lighter and faster under the code name Fenix prior to release. -->

Emphasized words refer to Firefox Focus, Reference Browser, and Firefox Reality, all of which had switched to the Quantum-based GeckoView for higher performance.