Mozilla and Microsoft are launching a new version of Firefox that defaults to Bing for its search options and homepage. The alternate version of the browser isn't substantially different from the standard build — it just ships with the Bing add-on preinstalled. The stock version of Firefox continues to ship with Google, but that deal runs out in November, when Mozilla says it'll "reassess" the situation; a change would be a huge boost to Bing and allow Mozilla to diversify its revenue sources.

Mozilla has never been shy about exploring the complicated relationship between open and closed sourced products — the company says it has nearly 20 versions of Firefox including ones made in partnership with Twitter and Yahoo.