A bit of history for you: The reason why we tend to use the metonym "Linux", as opposed to e.g. GNU/Linux like FSF begs, is because GNU is a victim of their own success.
In the 1980's whenever you got a UNIX machine no matter what the brand you installed a GNU userspace replacing whatever came with it because they appreciated GNU's quality. So once an opensource kernel came in the 1990's noone felt the need to mention which userspace they installed on it, ofcourse it'd be GNU!
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