Baker won't be going anywhere, as she takes on the role of chairman for the Mozilla Corporation. Lilly, the company's chief operating officer, moved up at Baker's request.

"John has been instrumental in developing an organizational structure for MoCo that is both embedded in Mozilla and open-source DNA and which can function at the extremely high degree of effectiveness that our setting requires," Baker said on her blog.

"Once I allowed myself to think about this I realized that John will be a better CEO for the MoCo going forward than I would be," she continued.

"We’ve got a lot to do in the coming years, starting with getting Firefox 3 out the door, and then swiftly followed up by our work in mobile and services," Lilly said of his new duties.

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