Barence writes "Firefox has just turned five, and it now accounts for 25% of the global market, according to figures from Net Applications. Its success has forced rivals to raise their game, and the past two years have seen Microsoft, Apple, and Opera close the features gap significantly. Google is the default homepage when Firefox first opens, and the default search engine when users type something into the 'awesome bar.' The deal, which runs until 2011, was worth $66 million to Mozilla in 2007, accounting for 88% of the foundation's revenues that year (the last year for which it had published accounts). But now that Google is a competitor as well as a partner, is it really wise for Mozilla to be so dependent on Google?"