Mozilla

Maker of Firefox and of the Gecko platform, which also carries Thunderbird and the downstream builds — zen among them. Mozilla publishes the platform’s engineering documentation openly, which is why this spoke can describe an engine’s internals first-hand rather than through vendor marketing, as it must for most Chromium browsers.

Beyond that, the spoke holds no sourced claims about Mozilla — the foundation/corporation structure, its revenue, and the Google search agreement are all unread here. Entity page kept deliberately thin until a source arrives.