The Mozilla Foundation's deal with Google is playing a crucial role in helping the non-profit organisation challenge Microsoft with its Firefox browser.

Following an agreement reached last year, Firefox includes Google as the default option for users wanting to search the Web directly, and also has its default start page hosted by Google. Markham didn't reveal full details of the Foundation's deal with Google.

Markham said the Foundation may sign more sponsorship deals in the future, but is cautious of making too many deals as this could have a negative impact on usability. He claims this is one problem that Netscape encountered.

"Netscape ran into trouble with its browser as it sold every bookmark and link, and couldn't change the browser in a way that was better for users without breaking its deals," said Markham. "We're very aware that Netscape fell into this trap and don't want to do same thing. Google was the default browser for Firefox before we even signed the deal."