Mercury is a Mozilla Firefox fork like Thorium for Chromium. It improves performance and applies several patches that disables bloatware from Firefox.
The version that I use is the AVX2 one (I’ve read that AVX2 is the most recent compiler optimization).
Themes
Additionally, I use another theme on top of Mercury: ShyFox.
Things to consider
https://github.com/Alex313031/Mercury/issues/63: sessions were beign destroyed and emptied. This was due to the LibreWolf patch.