Gal's rise to CTO comes under less-than-ideal circumstances. He's filling the role that Brendan Eich left in March for his short and controversial stint as Mozilla CEO.

Eich resigned after only nine days, amid an outcry over his 2008 support for a California law banning same-sex marriage. The controversy rocked the normally tight-knit community of developers that helps produce Mozilla's free, open-source Internet applications. Jay Sullivan, former chief marketing officer, is now acting CEO as Mozilla looks for a new boss. 

Gal, a six-year Mozilla veteran who most recently served as vice president of mobile, says he's confident the company can regroup. He's intensely focused on Firefox OS, a mobile operating system with big ambitions: winning the battle for the next two billion smartphone users.