Looks like a combination of JS and C++, see for example https://dxr.mozilla.org/comm-central/source/db/mork/src https://dxr.mozilla.org/comm-central/source/db/m

Looks like a combination of JS and C++, see for example https://dxr.mozilla.org/comm-central/source/db/mork/src https://dxr.mozilla.org/comm-central/source/db/mork/src