Well, given that YouTube is one of Google's most resource-intensive sites (remember that acquisition back in 2006?), I'd say that alone makes them a pretty heav

Well, given that YouTube is one of Google's most resource-intensive sites (remember that acquisition back in 2006?), I'd say that alone makes them a pretty heavy user; plus, that's just the bit they've open-sourced. The Go team makes constant reference to assorted internal infrastructure projects for which Google uses Go, but which have not been and which probably never will be publicized.