Millions of people use it.
It's hard to tell exactly how many people use it as their desktop OS, as it's free for download and you can use it on as many computers as you want. Still, recent estimates put the number at around 65 million (that's more than the population of the UK!).
Also, we shouldn't forget that most servers use Linux. So Facebook runs on Linux servers. As does YouTube. And Google. The list goes on.
Considering this, we can update our statistic to 1,802 million (see http://www.internetworldstats.com/stats.htm).
So really, even if we have Windows installed at home, we are all using Linux everyday. A better question would be: who isn't using Linux?
Linux is really just a kernel maintained by a core of developers, but accepting contributions from many. Linux distributions, which is probably what you are thinking of, exist by the hundreds and are worked on by thousands of people to greater or lesser degrees. It's entirely possible for one person to release a distribution.
one, Linus torualds.
The Linux kernel was originally written by Linus Torvalds (Linux is only one letter away from Linus) Over time most of the Linux kernel has been modified by many people in the open source community, however Linus still oversees the project.
Linux was created in 1991 by a Finnish college student named Linus Torvalds.
Since Linux is a collaborative development environment, everyone that has contributed to the project has usually written some of the documentation.
"Linux servers can help people in many different ways. To date, Linux is still one of the top computer operating systems out there. It all depends on what you need to do."
Operating systems using Linux are often found on servers, many popular sites' servers run Linux because of its stability and performance. Linux is also used by people wanting to learn how to build a kernel thru example, because Linux is open source, they can. Linux is also used by people who want to build a custom operating system for their needs.
I think it was the Linux kernel. There are many used with Linux now.
Linux is not illegal. Linux is a free, public license software modeled on Unix.
Many, many, many people.
The courses available for Linux include Linux server, Linux desktop, bash shell, and many others.
Jaques Derrida? I am not sure, but...
There are many websites where one can learn about fdisk and many other Linux commands including Linux Help, Tuxfiles, Computer Hope, Linux Questions and Linux Solved.
From any of the websites for the many Linux distros out there.