Most of that revenue came partnerships with search engine sites, Baker said. "The revenue is from the easy 'search' capabilities built into Firefox and the related revenue relationships with the search providers," she said.
On her blog, Baker said the financial information is becoming available because the foundation filed its 2005 tax returns, and she wanted to give an overview "because the steady revenue stream is so important to our long term sustainability."
The search revenue has "allowed us to continue to expand," she said. The foundation began with 10 employees stretched thin, but now generally has teams of people where it once had individuals.
She didn't release 2006 figures, but she said the foundation's 2003 revenue was $2.4 million and 2004 revenue was $5.8 million. The combined expenses of the Mozilla Foundation and a subsidiary, the Mozilla Corporation, were $8.2 million in 2005, she said.
The foundation oversees the open-source Firefox Web browser project as well as e-mail software called Thunderbird.