GNU is short for Gnu is Not Unix.
There official website is: https://www.gnu.org/
It started out of a philosophy that code should be FREE. <- Different then the term open source.
Also GNU idea of free is not free in money but free of retractions but uselessly nobody asks money for it but you are allowed to as long as the buyer has the same freedom you had with it.
http://www.gnu.org/philosophy/open-source-misses-the-point.html
RMS Wanted to point they don't advocate Open Source, but for free software and is unhappy if GNU logo's are used to promote open source, But a fact is open source doesn't have to be free. It depends on it licensing and afcourse who created it.
https://www.gnu.org/licenses/fdl-1.3.en.html
Fun licensing qoute from Steve Ballmer(former CEO of Microsoft).
Nice guy sadly terrible with choosing words, but i still think hes a good guy.
Linux is not in the public domain. Linux is a cancer that attaches itself in an intellectual property sense to everything it touches. That's the way that the license works.
It's also encourages software to be open so that you can observe to see what the software does under the hood and that you share with your fellow humanoids.
GNU and Linux are not the same.
Linux was ones build by Linus Torvalds in 1991.
He used the tools that the GNU made to create hes own Kernel. https://gcc.gnu.org/
Other people found this Kernel saw it was Unix and though "Hey we can use GNU software and the Linux kernel to make one working OS with tools".
GNU adopted this kernel because GNU Hurd there own OS kept failing which they started before Linux existed (it finally works now, but it still not suitable to work with).
https://www.gnu.org/software/hurd/ <- Get your free copy today and forever :)
Linus himself liked open source because it stimulated development. He didn't started Linux to create a open source project it came to him and he later found out how well it worked out for Linux. He sometimes get annoyed with GNU because people mistake them for being the same and that GNU and FSF used Linux to promote Free software.
https://en.wikipedia.org/wiki/Free_Software_Foundation_anti-Windows_campaigns _Linux
Linux used to get named a lot during these campaigns. This frustrated Linus because he doesn't want to become the Anti-Windows but he want's the people to use Linux because they think its the best OS for there jobs and hobby's.
GNU/Linux refers to the Operating Systems that are listed on there website. http://www.gnu.org/distros/free-distros.html.
Other Linux versions (but also BSD and Solaris) can be found here.
https://distrowatch.com/
For me and most Linux user (Am not chosen to speak for them, but i do anyway).
Linux is just a highly configurable operating system that is also that inspires high creativity among its users.
if you are sick of linux: " https://en.wikipedia.org/wiki/List_of_operating_systems "
I wanted to sum up some but besides Linux/BSD (They all are separated OSes) and Windows theres a shitload of them inlcuding solaris/AmigaOS/Minix. OK busted i just summed up some! Up yours, you already read it anyway, still not satisfied ugh...Go use Apple!.
But just using Linux doesn't mean you are forced to approve of open source or free software. There are a lot of implantation of Linux were you need to pay money to use it. Red Hat perfect example.
Movie you should watch if you are interested in Linux and GNU: Revolution OS.
I found it very interesting myself. It's a documentation about GNU and how the Linux kernel was born and become widely adopted over the entire world and not just like Windows and Apple only in the rich western world.
I hope its a good summery or that it explains some stuff and that helps for this website.
More information about this. See the movie or go to https://www.gnu.org/.
GNU has entire database of old documents about this subject and what is what.
I really encourage people to read some of it. Its interesting to see what this organization does and how it effects your daily life with computers.
https://fsf.org/
Free Software Foundation is the critical infrastructure and funding for the GNU project.
https://www.linuxfoundation.org/
The similar for for Linux.
Easy to follow movie to understand benefits of open source.
Also if something is wrong or i worded it wrong. Just post it here.