On September 27, 1983, computer scientist Richard Stallman announced the plan to develop a free software Unix-like operating system called GNU, for "GNU's not Unix."
The Foundation said that GNU is the only operating system developed specifically for the sake of users' freedom, and has remained true to its founding ideals for forty years. Since 1983, the GNU Project has provided a full, ethical replacement for proprietary operating systems.
Stallman said: "with a free operating system, we could again have a community of cooperating hackers — and invite anyone to join. And anyone would be able to use a computer without starting out by conspiring to deprive his or her friends."
Free Software Foundation executive director Zoë Kooyman said that when looking at the history of the free software movement — or the idea that users should be in control of their own computing — it starts with GNU,.
"The GNU System isn't just the most widely used operating system that is based on free software. GNU is also at the core of a philosophy that has guided the free software movement for forty years."
Usually combined with the kernel Linux, GNU forms the backbone of the Internet and powers millions of servers, desktops, and embedded computing devices. Aside from its technical advancements, GNU pioneered the concept of "copyleft," the approach to software licensing that requires the same rights to be preserved in derivative works, and is best exemplified by the GNU General Public License (GPL).
Stallman said: "The goal of GNU was to give users freedom, not just to be popular. So we needed to use distribution terms that would prevent GNU software from being turned into proprietary software. The method we use is called 'copyleft.'"
The free software community has held strong for 40 years and continues to grow, as exemplified by the FSF's annual LibrePlanet conference on software freedom and digital ethics.
Kooyman continues, "We hope that the fortieth anniversary will inspire hackers, both old and new, to join GNU in its goal to create, improve, and share free software around the world. Software is controlling our world these days, and GNU is a critique and solution to the status quo that we desperately need in order to not have our technology control us."