All of google's backend code is written on Linux desktops. OSX is common for laptops, but real code isn't permitted to touch their drives.

> but real code isn't permitted to touch their drives

Do you mean one is not allowed to check out the code on OSX and sync to the dev/linux box?

When I was there, that's exactly how it worked. Obviously not the case if you were doing OSX or iPhone dev, but otherwise no code on your laptop.

That's a security rule, not an anti-OS X rule.

I still bet that the majority of engineers at Google use OS X on their primary laptops (and they still wouldn't be allowed to put the code on their laptops, even if the laptops were Linux).

This might be true but I imagine at least some of their employees use Linux and would like to use drive from Linux.