Linux is not GNU It is true that the bulk of most Linux systems is made up of GNU software but the core of the system is not and has never been part of project GNU and indeed apart from GCC it is possible to build an entire Linux system using non GNU software You d be giving up a lot of functionality doing that mind you but there are those who would argue that you re also removing massive amounts of bloat from the equation a flamewar for another time Therefore it is incorrect to include Linux as part of GNU