Yup, the amateur hour OS on nearly every supercomputer on the planet, powering most smart phones on the planet, and so many myriad other devices its staggering.
Amateur hour at its finest -- owning the planet.
That's now competing head to head against "professional" operating systems on every platform imaginable and actually winning in mobile, server and supercomputer.
(Anecdote... my brother's wife bought him a new TV last year for Xmas, we were testing it out with various inputs when I noticed the... get this... copyright notices in the menus...
"Dude, your TV is running Linux..."
"No seriously, check out that list of opensource components... and at the bottom?"