Av. Tibidabo, 39-43, 08035 Barcelona2009-09-01 1
GNU/Linux systems [Joh98] are no longer a novelty; they have a broad range of users and they are used in most work environments.
Their origin dates back to August 1991, when a Finnish student called Linus Torvalds announced on a news list that he had created his own operating system and that he was offering it to the community of developers for testing and suggesting improvements to make it more usable. This was the origin of the core (or kernel) of the operating system that would later come to be known as Linux.
Separately, the FSF (Free Software Foundation), through its GNU project, had been producing software that could be used for free since 1984. Richard Stallman (FSF member) considered free software that whose source code we could obtain, study, modify and redistribute without being obliged to pay for it. Under this model, the business does not reside in hiding the code, but rather in the complementary additional software, tailoring the software to clients and added services, such as maintenance and user training (the support we give) whether in the form of materials, books and manuals, or training courses.
The combination of the GNU software and the Linux kernel, is what has brought us to today's GNU/Linux systems. At present, the open source movements, through various organisations, such as the FSF, and the companies that generate the different Linux distributions (Red Hat, Mandrake, SuSe...), including large companies that offer support, such as HP, IBM or Sun, have given a large push to GNU/Linux systems to position them at a level of being capable of competing and surpassing many of the existing closed proprietary solutions.
GNU/Linux systems are no longer a novelty. GNU software started in the mid-eighties, the Linux kernel, in the early nineties. And Linux is based on tested UNIX technology with more than 30 years of history.
In this introductory unit we will revise some of the general ideas of the Open Source and Free Software movements, as well as a bit of the history of Linux and its shared origins with UNIX, from which it has profited from more than 30 years of research into operating systems.