The title pretty much says it all. I am using Ubuntu Mate, so Firefox is available from the main repository.
Firefox has not worked on the Raspberry Pi since Firefox 55. I hoped that Firefox 56 would fix the issue, but it did not. Now apparently the latest Firefox (57) has been rebuilt to some degree, and although the chances of the bug being fixed is slight, there is always hope.
Has anyone tried it yet? If so, please post your results. If nobody posts, I will be the guinea pig.
Thank you.
Update: Firefox 64 is working with Ubuntu Mate 18.04
No, it does not!
Anyone who would like to use Firefox on the Raspberry Pi will still have to use an old version, preferably Firefox ESR (the latest ESR available on Raspbian is now 52.5.2 ESR, as of Dec 29, 2017).
I hope that this issue will be resolved before long, but unfortunately this does not seem very likely.
From what I have read elsewhere, nobody wants to take responsibility for the issue.
It seems to be possible to use Firefox 57 on the Raspberry Pi 3 running Ubuntu, by using 64 bit, see jdonald´s answer.
As your question is specific to Ubuntu MATE, I have confirmed a workaround but it won't work on anything older than a Pi 3. You can take advantage of Ubuntu's support for MultiArch.
Switch your kernel to 64-bit. The bootloader included with Ubuntu MATE Xenial already checks for kernel8.img. You can take the Pi64 Lite image and copy over its /boot/{kernel8.img,*.dtb,overlays,cmdline.txt,config.txt} along with the contents of /lib/modules/. Of course, back up your existing 32-bit kernel configuration beforehand. Reboot (fingers crossed). I was surprised that going from kernel 4.4 to 4.11 doesn't cause obvious problems.
Set up MultiArch.
sudo dpkg --add-architecture arm64 && sudo apt update
Install and run 64-bit Firefox:
sudo apt install firefox:arm64 libcanberra-gtk3-module:arm64 topmenu-gtk3:arm64
firefox
(I initially got some warnings about missing Canberra and Topmenu GTK modules, hence the two additional packages.)
Update: Somewhat quicker approach that works on a Pi 2: First, if you're on Ubuntu MATE Xenial download the Trusty .deb package and use dpkg --install. Next, disable Skia then go ahead and run 32-bit Firefox.
try the fix on my RPI2 with ubuntu mate 16.04. Finally it works when, I put in comment all the lines user_pref containing gfx
