Recently I was also informed of a new place TenFourFox code has turned up: OS/2. There's no Rust for OS/2, so they're in the same boat that PowerPC OS X is, and it doesn't look like 52ESR was ever successfully ported to OS/2 either; indeed, the last "official" Firefox I can find from Bitwise is 45.9. Dave Yeo took that version (as well as Thunderbird 45.9 and SeaMonkey 2.42.9) and backported our accumulated security patches along with other fixes to yield updated "SUa1" Firefox, Thunderbird and SeaMonkey builds for OS/2. If you're curious, here are the prerequisites.
Frankly, I'm glad that we can give back to other orphaned platforms, and while I'm definitely not slow to ding Mozilla for eroding cross-platform support, they've still been the friendliest to portability even considering recent lapses. Even though we're not current on Firefox anymore other than the features I rewrite for TenFourFox, we're still part of the family and it's nice to see our work keeping other systems and niche userbases running.
An update for FPR14 final, which is still scheduled for mid-May, is a new localization for Simplified Chinese from a new contributor. Thanks, paizhang! Updated language packs will be made available with FPR14 for all languages except Japanese, which is still maintained separately.