mozilla employs at the moment around 800 people.
according to their FAQ
> https://www.mozilla.org/en-US/foundation/annualreport/2015/f...
> More than 75% of Mozilla spending is on people-related investments to produce the products and programs that support our mission: keeping the web open, free, and accessible.
this would mean they had around 300 million to spend on these 800 employees, averaging around 375 000 per employee.
Sr. Software Engineers get <$200 000, so IF all of their 800 employees were senior software engineers (extremely unlikely), their salary would be around 160 million, which is slightly more then 50% of what was available. a more realistic calculation would be around 20-30%, because not everyone will be getting SV wages. They've got global presence after all with offices SF, Toronto, Berlin, Beijin etc.
you'd have to verify in which unrelated projects by third parties mozilla invests and generally follow the money to figure out anything more, but that is simply out of scope of a hn comment.