GNU/Linux
Linux is a free Unix-type true multitasking operating system originally developed by Linus Torvalds as a young student in Finland, it was started as a hobby in April of 1991. The project quickly took off and has since been developed with the assistance of developers around the world and is still maintained by Linus to this date. Developed under the GNU General Public License, the source code for Linux is freely available to everyone. Linux refers to the kernel (the core of an operating system), but most of the basic OS tools come from the GNU project, hence the name GNU/Linux. Many aren't aware of the importance of GNU in relationship to Linux, Linux would not be where it is today without the existence of the GNU project.