Mozilla Corp., maker of the Firefox browser, has promoted COO John Lilly to chief executive, replacing long-time CEO Mitchell Baker, who’s been with the open source project since the Netscape days. Baker will stay on as chairman of the Mozilla Corp. and the Mozilla Foundation that controls it. She will also maintain her more informal title, that of “Chief Lizard Wrangler.”

The transition is amicable by all accounts — the press release, Baker’s blog post and Lilly’s blog post. Lilly will apparently ramp up technology execution (Hear hear! I, like many, have a sort of emotional attachment to Firefox but am mighty fed up with how it heats up my laptop, eats up my battery and crashes far too often), while Baker works on public outreach projects about the organization and its unorthodox methods.

Mozilla’s revenue, mostly due to its search partnership with Google, is eye-catching ($67 million in 2006!), and the CEO change will no doubt turn up the Mozilla IPO chatter — it’s the same cycle that continually afflicts other more altruistic tech projects like Craigslist and Wikipedia. But the company/foundation continues to insist that going public isn’t in the cards.