What about us?
Here it is like half Windows, half Linux.
The dividing line goes approximately between people just using commercial software and people creating their own tools (the latter would not be considered normal users in an office but in a physics department it is different). While Macs can do both and there is usually a way to get most Windows and Linux software working, the appeal to people either locked deeply in Windows software or accustomed to open source environments and tools is kind of limited...