Change OS names at the TBB donwload page
At https://www.torproject.org/projects/torbrowser.html.en The OS names must be, Microsoft Windows, Apple MacOS and GNU/Linux
Apple renomed they OS from OS X to MacOS
and GNU Project have somer arguments about use GNU/Linux instance of just Linux, as the Linux is just a kernel. http://www.gnu.org/gnu/gnu.en.html
Trac:
Username: i139