Of the many controversies in free software, this is one that I have long found to be interesting. People seem to define things in different ways, which leads to confusion (and arguing) when one person calls a system a "GNU/Linux" system and the next calls it just the "Linux" system. Too often, I have found people saying "You must always call it GNU/Linux, Linux is nothing without GNU!" and this is simply incorrect. So, here I try to spell out the issues and when something is "GNU/anything" and when it is not.