Back in the Day: Unix, Minix and Linux
With a lot of help from others in the digital world, Stallman started building GNU (which literally stands for GNU is Not UNIX), and along the way, he created the Free Software Foundation. The Free Software Foundation ended up being responsible for a lot of the building blocks of Linux and modern UNIX systems, notably the compilers. You can thank AT&T Bell Labs, UC Berkeley’s Computer Science Research Group, MIT’s Media Lab and a whole lot of us aficionados for creating the system you know and love.
Source: www.linuxjournal.com