I keep meeting people that get this wrong and start very boring discussions about the name of operating systems based on Linux kernel. Latest storm started with Pedro Côrte-Real ‘How much GNU is there in GNU/Linux’ and the subsequent comments on LWN.net. GNU is the foundation of a very powerful idea: that one day computers would run on a free (as in freedom) operating system. GNU is not an operating system, GNU cannot be measured in lines of code. The lines of code of GNU that are copyright by the FSF are what made everything else available, from Linux to Android to Apache. If it wasn’t for the early years of development of the GNU system by Stallman we would have probably never had what we have now.
Call it whatever you think is fair but remember that this is not about lines of code, it’s not a technical issue: calling the system GNU/Linux is paying a tribute to the idea that computer users need to have a free operating system. I wish the FSF would make this more prominent on gnu.org.