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. Mozilla, the nonprofit behind the Firefox web browser, saw its revenue increase 24 percent in 2016 to $520 million. Most of Mozilla's money comes from partnerships with search engines like Google, Yahoo, DuckDuckGo, Baidu and Yandex. When you search through Firefox's address bar, those search engines show search ads alongside results and share a portion of the revenue to Mozilla. Mozilla in 2014 signed a major five-year deal with Yahoo to be the default search engine in the US, but canceled it only three years in and moved back to Google instead in November. Mozilla's mission -- to keep the internet open and a place where you aren't in the thrall of tech giants -- may seem abstract. But Mozilla succeeded in breaking the lock Microsoft's Internet Explorer had on the web a decade ago, and now it's fighting the same battle again against Google's Chrome. For example, room-rental service AirBnB and discount shopping site Groupon this week both said their sites are optimized to work on Chrome -- though Groupon later said it supports all major browsers. Tailoring sites just for the dominant browser is the kind of thing that undermines the web as a neutral platform. Mozilla also has political work under way like fighting for net neutrality and defending encryption. All this is why Mozilla poured resources into overhauling Firefox, an effort that culminated in this month's release of version 57, also called Firefox Quantum. The browser is faster, and performance improvements leading up to it helped stop Firefox users from defecting to other browsers, Mozilla has said. Mark 57, a Firefox-themed takeoff on an Iron Man suit, served as