Mozilla cuts off support for macOS releases much too early in my opinion. I'm running macOS 10.14 Mojave which was released in 2018 and it only supports FireFox 91. The latest version of FireFox is 96. I can't find a definitive statement what minimum version of macOS is needed by the latest Firefox, but what they list on https://www.mozilla.org/en-US/firefox/96.0/system-requiremen... is incorrect and/or out of date: macOS 10.12.
EDIT: I was wrong. mrpippy pointed out in a reply below that Mojave is still supported by the latest FF release. I was using the FF ESR release which only goes up to FF version 91. Sorry for the noise, and thanks for correcting me.
Just a quick digression: If you decide to upgrade from Mojave to Big Sur, make sure you create a bootable USB installer first, and back up anything that you don't want to lose. I decided to upgrade because Mojave is no longer getting security updates, but ran into some issues took 2 entire days to resolve.
During the in-situ upgrade process, I probably got hit with this installation bug (https://en.wikipedia.org/wiki/MacOS_Big_Sur#Criticism) where the installer never finishes if you have more than 20,000 folders in an obscure folder. I'll never know because I was forced to wipe the disk and perform a clean install. But before you wipe your disk, do a search for "Macintosh HD - Data" and "Macintosh HD - Data - Data", because the Big Sur installer is apparently not idempotent, so you need to delete the "Macintosh HD - Data" volume if the installer breaks halfway through the process.
You should create the USB installer before all this because the clean install may download the Big Sur image, then throw it away, and proceed to download and install Snow Leopard instead. At least that's what happened to me. But Snow Leopard not have the certificates necessary to connect the App Store. So the machine can't download the Big Sur image anymore. The only way around that is to own a second Mac to download the image and create the bootable USB drive for Big Sur, and do another clean install.
On the other hand, Mozilla has fewer resources to spend on maintaining backwards compatibility. Mojave is pretty old as far as continuously updated operating systems are concerned, and the devices that didn't get the Mojave update are all over 10 years old at this point.
The hardware itself is supported just fine; install Linux on your 2011 Macbook and you can download the latest and greatest Firefox release. Mozilla just doesn't spend much time on operating systems that have fallen out of support. I don't expect them to keep their Windows 7 builds going for long once Microsoft ends their paid support programme.
If Apple doesn't bother publishing regular security and maintenance updates, then why should Mozilla? Users shouldn't be running operating systems that receive no or only some security patches anyway.
Upgrading or switching the OS is a major undertaking.
I appreciate that Mozilla has fewer resources than Google, but having the latest version of FireFox working only on macOS versions released within the past two years is unnecessarily restrictive in my opinion. I'm an independent software developer far more financially constrained than Mozilla who supports macOS releases going back 10 years. It's just a matter of not using the new API calls shipped with each new OS release and optionally dynamically loading the API calls that are not present on all OS versions.
EDIT: My original post was wrong. Mozilla still supports Mojave. See details above.
I’m also running Mojave, and am still getting Firefox updates. Not sure why you aren’t, and I think their stated support back to 10.12 is still accurate.
Years ago I wrote a small toy interpreter based on predereferenced computed gotos with surprisingly good speed. For very small programs without dynamic data allocation churn it could run as fast as 3 times slower than compiled code instead of the expected 10X slower. Good things happen speed-wise when all the byte code and data fits into the L1 cache. Also, branch prediction is near perfect in tight loops.
For whatever reason I can never remember the syntax of <(command) and end up "rediscovering" it every year. It's seldom used but when it's needed it's rather elegant.
Another somewhat related useful bash feature is using this form:
With the caveat that the here string causes a tempfile to be written¹, so they're not quite equivalent. How much that matters for your use cases though is a different question, but it is worth thinking about if you're doing lots of repeated calls.
¹ With Bash v5 it may use a pipe if the data is small enough, but you can't guarantee people will have that because of GPLv3 phobia. I believe it is always a tempfile with zsh.
More complex than autotools? You can cut your build times dramatically even if you’re far from google scale. The improvement we saw at current co was 10x. Try that with autotools
Contrast that support with Google Chrome, its latest browser works on OS X El Capitan 10.11 from 2015: https://support.google.com/chrome/a/answer/7100626?hl=en - which is much more reasonable.
EDIT: I was wrong. mrpippy pointed out in a reply below that Mojave is still supported by the latest FF release. I was using the FF ESR release which only goes up to FF version 91. Sorry for the noise, and thanks for correcting me.