Here are Mozilla's financials (PDF, covers 2022 and 2023), and skme highlights:
- "royalties" (Google) - ~$500M
- investment income - $10-50M ($1B in investments)
- SW dev expenses - $220-260M
They're putting quite a lot of that Google money into investments, probably in case the gravy train dries up.
Mozilla has ~750 employees, about 700 of which work on Firefox in some capacity.
So, if we take $260M/700, we get $370k per employee. That's pretty high, though I guess it makes more sense in SF. If they moved their operations to a less expensive state, they could cut that in half or more.
However, if the Google money ends, they would need to drastically cut their workforce, like by more than half, or raise a ton of cash some other way.