The main "engine" is here: https://searchfox.org/mozilla-central/source/browser/extensions/webcompat/lib/shims.js https://searchfox.org/mozilla-central/source/b

The main "engine" is here: https://searchfox.org/mozilla-central/source/browser/extensions/webcompat/lib/shims.js https://searchfox.org/mozilla-central/source/browser/extensi... The shims are here: https://searchfox.org/mozilla-central/source/browser/extensions/webcompat/shims/ https://searchfox.org/mozilla-central/source/browser/extensi... And the config file for how they are used is here: https://searchfox.org/mozilla-central/source/browser/extensions/webcompat/data/shims.js https://searchfox.org/mozilla-central/source/browser/extensi...