Main repository: https://github.com/M-Reimer/togglefonts.
AMO: https://addons.mozilla.org/firefox/addon/togglefonts/
Localization: https://lusito.github.io/web-ext-translator/?gh=https://github.com/M-Reimer/togglefonts/
Hacking: Do a temporary install.
Building: make