Hi:
The GNU General Public License-
is a software license ensuring that the source code for any operating system remains freely
available for anyone that wants to examine, build on or improve upon it.
A man named (you can find him online) Mr. Richard Stallman developed and designed the GNU Project.
This wikipedia page should help.
http://en.wikipedia.org/wiki/Richard_Stallman
And this website too-
http://en.wikiquote.org/wiki/Richard_Stallman