Google would still be a garage startup without open source. That small startup would never have been able to afford to build the required server farms for Google Search, if it had had to pay for commercial license for all those machines. Arguably, the biggest reason for Google taking over the search market wasn't their superior search algorithms, but being one of the first companies to truly take advantage of Linux servers on massive scale.

Oh and then there's that Google OS based on open source code. It's called Robot or something like that.