What is GNU / Linux
The Linux Operating System — more precisely called GNU / Linux — is made of two parts: the Linux Kernel and the tools from the GNU project. Together they form a fully functional operating system. Continue reading to understand what each part contributes.
The Linux Kernel
In 1991, Linus Torvalds, a student at the University of Helsinki in Finland, started the Linux project as a side project trying to emulate MINIX — a Mini-Unix created for educational purposes by Andrew Tanenbaum.
After working with MINIX at university, Torvalds started developing Linux. It differed from MINIX in one fundamental characteristic: the kernel architecture.
Micro kernel
Only the most basic functions run in kernel mode. Drivers, file systems, and other services run in user space, above which sit the applications. MINIX uses this architecture.
Monolithic kernel
All functions that are not applications run in kernel mode. Linux is a monolithic kernel — some drivers can be loaded as modules in user space, but the core architecture is monolithic.
Image source: Wikipedia
The GNU project
In 1983, Richard Stallman started the GNU project:
The GNU project is a mass collaboration of programmers who seek to create a completely free and open operating system that was similar to Unix but with completely original code.
— Wikipedia
The GNU project produced all the applications and tools that run on top of a kernel — compilers, shells, utilities, libraries. When Torvalds released the Linux kernel, it was combined with the GNU tools to create a complete, working system.
Why GNU / Linux, not just Linux
Linux by itself is only a kernel — not an operating system. The GNU project without a kernel is also not an operating system. Together they are the GNU / Linux Operating System.
An operating system can be defined as a kernel plus the tools needed to control the hardware and run applications. That is exactly what GNU + Linux provides.
Calling it GNU / Linux gives credit to both contributors: Linus Torvalds and the thousands of developers behind the kernel, and Richard Stallman and the GNU project contributors who built everything else.
- Created: April 14, 2013
- Last edited: July 7, 2026