Firefox’s PowerPC fork, which lasted for over a decade, has reached the top of the highway


Enlarge / An old PowerBook G4 with Mac OS X 10.5 Leopard, Microsoft Word 2008 and the TenFourFox browser.

Andrew Cunningham

It’s been well over a decade since PowerPC Macs roamed the earth – so long that the Intel Macs they replaced were themselves replaced with something else. But to this day there is a small community of people still developing software for PowerPC Macs and Mac OS 9.

One of these projects was TenFourFox, a fork of the Firefox browser for G3, G4, and G5-based PowerPC Macs with Mac OS X 10.4 or 10.5. The TenFourFox project, primarily supervised by Cameron Kaiser, came into being at the end of 2010 after Mozilla discontinued Firefox 4 PowerPC support during its development. And amazingly, the browser has continued to evolve since then.

But over time it became more and more difficult to port Firefox functions back to outdated PowerPC processors. And in March of this year Kaiser announced that TenFourFox updates will be discontinued after over a decade of development. The last scheduled release of TenFourFox was earlier this month.

Kaiser’s full post is long, but well worth reading for vintage computer enthusiasts or anyone working on software of modern day internet and open source software development, saying:

I am also proud of the considerable number of TenFourFox functions that have been successfully backported or completely redesigned. TenFourFox was the first and still one of the few browsers on PowerPC Mac OS X to support TLS 1.3 (or even 1.2), and we are the only browser of its kind with JavaScript JIT. We also completed a few features that were long planned for mainline Firefox but never made it, such as our AppleScript (and AppleScript-JavaScript Bridge) support. With our implementation, you can even manipulate web pages that may not work properly to function properly. Over the decade that TenFourFox has existed, we also have our own native date and time controls, basic ad unit, advanced reader view (including sticky and automatic functions), additional media support (MP3, MP4 and WebP), additional functions and Implemented syntax for JavaScript, and AltiVec acceleration in all possible parts of the browser. There are also tons of backported bug fixes in large parts of the browser that fix long-standing problems. All of this kept Firefox 45, our optimal platform base, useful well past its best before date and made it an important resource for other older browsers (including, incredibly, OS / 2).

[T]he biggest investment is time: trying to keep a regular schedule when the ground shifts under your feet is a huge part of my free time, and since my regular job is highly specialized and has little to do with computers, you can’t pay for it really enough to devote my daily life to TenFourFox or some other open source project because I just don’t scale. (We never accepted donations anyway, mostly to keep people from thinking they were “buying” something.) I know that some people make all of their living doing free, open source projects. I think these people are exceptional and noteworthy precisely because of their rarity. Most open source projects, including those with large user bases, are ultimately black holes and always will be.

Kaiser does not intend to stop working on the browser entirely, but is moving it to what he calls “Hobby Mode”. He will continue to backport security patches from newer ESR versions of Firefox and post them on the TenFourFox Github page, but anyone who wants to use these will have to create the app themselves. Also, Kaiser will not undertake to endorse these supplements or provide them on any schedule. Other developers are also welcome to continue to self-publish TenFourFox builds.


There are many reasons why you might not want to browse the 2021 web on a PowerPC Mac, even with a fully supported browser. G4 and G5 processors are an order of magnitude slower than modern Intel, AMD, or Apple Silicon processors, and trying to load a bloated modern website onto a computer with only a gigabyte or two of RAM is a frustrating exercise.

In addition, it has been years since Mac OS X 10.4 or 10.5 received security updates, and most third-party app developers have long since moved on. Old computers can still run old software, as I learned in 2014 when I tried running Mac OS 9, but getting online or trying to interact with other computers is more difficult. TenFourFox and its development blog are proof of how difficult it can be to swim against this current.