They actually maintain at least four browser codebases: Chrome, Android's Webkit, Picasa (uses Gecko), and their server-side renderer. They have at least three

They actually maintain at least four browser codebases: Chrome, Android's Webkit, Picasa (uses Gecko), and their server-side renderer. They have at least three product OSes: ChromeOS, Android, and The Google Search Appliances. This is at least their second new programming language project: there's also Rob Pike's Sawzall. They have numerous in-house implementations of existing programming languages: V8, Closure, GWT, Dalvik, Unladen Swallow, plus all the extant ones they maintain forks of.