"The GNU operating system is a complete free software system, upward-compatible with Unix. GNU stands for “GNU's Not Unix”. Richard Stallman made the Initial Announcement of the GNU Project in September 1983. A longer version called the GNU Manifesto was published in September 1985 [...] By 1990 we had either found or written all the major components except one—the kernel.

"Richard Matthew Stallman (born March 16, 1953), often abbreviated "rms",[1] is an American software freedom activist, hacker,[2] and software developer. In September 1983, he launched the GNU Project[3] to create a free Unix-like operating system, and has been the project's lead architect and organizer.

"Twenty five years ago , on September 27 1983, Richard Stallman announced his plans to 'write a complete Unix-compatible software system called GNU (for Gnu’s Not Unix), and give it away free to everyone who can use it'..."

Linux is a UNIX like operating system and has been one of the most popular proponents of free open source software. Even though popularly GNU/Linux is called Linux operating system, but the name is somewhat misleading because Linux is the name of the kernel of the operating system, which was created by Finnish hacker Linus Torvalds as a hobby project

"...The Free Software Foundation Europe, and the Royal Institute of Technology organized a lecture with Dr. Richard Stallman. Mainly the session was about the free software movement and the GNU/Linux operating system. Richard Stallman spoke about the goals and philosophy of the Free Software Movement, and the status and history of the GNU operating system, which in combination with the kernel Linux is now used by tens of millions of users world-wide..."

"Last week I got the opportunity to fire questions to unarguably one of the most influential and inspirational people of our time.

"The GNU/Linux naming controversy is a dispute among members of the free and open source software community relating to the normative branding of the computer operating systems commonly referred to as Linux.

GNU/Linux is the term promoted by the Free Software Foundation (FSF), its founder Richard Stallman, and its supporters, for operating systems that include GNU software and the Linux kernel.[1] The FSF argues for the term GNU/Linux because GNU was a longstanding project to develop a free operating system, of which the kernel was the last missing piece..."

Debian is a free operating system (OS) for your computer. An operating system is the set of basic programs and utilities that make your computer run. At the core of an operating system is the kernel. The kernel is the most fundamental program on the computer: It does all the basic housekeeping and lets you start other programs.

"Richard Stallman will speak about the goals and philosophy of the Free Software Movement, and the status and history of the GNU operating system, which in combination with the kernel Linux is now used by tens of millions of users world-wide..."