I was reading Richard Stallman's interview in a local Linux monthly the other day and was struck by an important point he was trying to make. The operating system we have all come to love, is not Linux! Let me explain...
Richard Stallman started the GNU Project in 1983-84 as a way of bringing back the cooperative spirit that prevailed in the computing community in earlier days. The project had the objective of developing a complete free operating system which could be shared in its source as well as binary form so that it could benefit the owner-user. By the 1990s, most major modules had already been written.
What was still missing was the kernel, the program that allocates the computer's resources to other programs. This is where Linus came in. In 1991, Linus Torvalds finished writing Linux, the kernel. Since almost everything necessary to make a Unix-like system was already available in the GNU project, the next logical step was to combine the two. This is how GNU/Linux, the (GNU) operating system, was born.
In time, individuals, university students and companies began distributing GNU/Linux-based operating systems with their own choice of packages bound around Linus' kernel. This is where the concept of the "distribution" was born. A Linux distribution is a collection of software packages built around the Linux kernel and the GNU operating system modules. These generally include a system installer, a system package manager based on the package management philosophy of that distribution, some custom developed packages in keeping with the objective of the distribution, and a carefully chosen set of freely available open source application packages.
Today, creating and selling Linux-based distributions is a multi-million dollar business. Major distribution companies such as Red Hat, SuSE, MandrakeSoft and others, offer boxed versions of their GNU/Linux distributions. Most initial distributions were aimed at the server market. Lately, however, most major distribution companies are exploring the prospects of their distributions on desktop computers. Their distributions normally include one or more window managers (desktop environments) in addition to the software collection mentioned above.
Most references to GNU/Linux nowadays drop the GNU prefix, refering to it as just "Linux." While this may be a result of a human tendency toward convenience, one must not forget that the GNU/Linux operating system that we use today had its roots in the GNU project, and still carries its mark in the GPL-ed programs bundled with it.