Alex Faaborg, a principal designer of the Firefox UI, announced that he is leaving Mozilla.
Faaborg joined the browser maker in 2006 and was a lead designer of the Firefox location bar and the most recent interface change of the browser. He also led the effort on the Sync interface of the addition of the home tab to the browser.
Faaborg's departure follows vice president Mike Shaver, who left Mozilla to join Facebook. Firefox director Mike Beltzner resigned shortly after the release of Firefox 4 for a new position at DownUnder GeoSolutions. Faaborg said that he will do "design work" in an entirely different space, but did not reveal where that will be.
Faaborg is the third key personality to leave Mozilla in less than a year and, while there is still a core team of highly visible people in place, it appears that Mozilla might be changing - which isn't necessarily a bad thing, given the challenges ahead and the need for Mozilla to evolve.