The nonprofit pulled in more than a half billion dollars. Now it's spending it on making Firefox worth using again.Well, now we know what paid for all those programmers cranking out the overhauled Firefox Quantum browser: a major infusion of new money.Mozilla, the nonprofit behind the open-source web browser, saw its 2016 revenue increase 24 percent to an all-time high of $520 million, it said Friday. Expenses grew too, but not as much, from $361 million to $337 million, so the organization's war chest is significantly bigger now. Mozilla, which now has about 1,200 employees, releases prior-year financial results in conjunction with tax filings.