What is GNU?

What it is

The GNU Project set out to write a whole operating system in which every user has the four freedoms of free software. It produced most of the parts: the GCC compiler, the core utilities such as ls and cp, and the Bash shell.

Its own kernel, Hurd, was never finished for everyday use. The Linux kernel filled that gap, so a typical Linux server is GNU tools running on the Linux kernel. Some people call it GNU/Linux for that reason.

The project also wrote the GNU General Public License, or GPL. It is a copyleft license: anyone who distributes the program, changed or not, must offer the source code under the same terms. Many open source projects use it.

Why it matters to a business

• Skills transfer: the commands your administrators type on a Linux server are largely GNU tools, and they work the same from one distribution to the next.
• Public maintenance: GCC and Bash are developed in the open, so their code and bug history can be checked by anyone.
• Running GPL software: using it inside your company generally adds no obligation. The AGPL, a variant, is the exception to check for, because it can apply when you let outside users reach a modified program over a network.
• Shipping GPL software: if you give a GPL program to customers, for example inside a device or an installer, you must provide the source and keep the same license.

How this shows up in our work

The Linux servers we build and maintain on Ubuntu, Debian and RHEL-family systems all include GNU tools. So do the Proxmox VE hosts in our own infrastructure. We also maintain public open-source tools of our own, and when we build software for a client we check the license of each part we use, the GPL included.

Learn more

• The GNU Operating SystemThe project home page, with its philosophy and software list, for readers wanting the original source.
• GNU on WikipediaA neutral history of the project and the GNU/Linux naming debate, good for general readers.
• GNU General Public License, version 3The full license text, for anyone distributing GPL software.
• GNU General Public License on WikipediaA plain overview of how the GPL works and its versions, useful before the legal text.