Mozilla's relationship with Google is "more complicated" after the search engine giant launched its own browser, John Lilly, Mozilla's CEO, has revealed.

"We have a fine and reasonable relationship", said Lilly. "But I'd be lying if I said that things weren't more complicated than they used to be".

Google recently launched Chrome out of beta - much earlier than expected - announcing that the browser had notched up 10 million users.

As Chrome saw a full release, Google swapped it for Firefox as the default browser in its Google Pack application bundle.

But, Firefox has seen a 24% increase in market share since the beginning of the year, something Lilly is quick to point out:

"At this point, one in five users of the Internet uses Firefox. That's good, and we're proud of that. When we launched Firefox 1.0 [four years ago], the odds of getting to 20%, most would have said that was impossible".

And, Lilly says, Mozilla is quite prepared to compete with Google: "We collaborate with Google, we talk to them and we have a fine and reasonable relationship. But we'll compete. This is, after all, user driven".