A brief history of open source software

Although all the stories related to software are obviously short, that of open source software is one of the longest amongst them. In fact, it could be said that in the beginning, there was only free (libre) software. Later on, proprietary⁴software was born, and it quickly dominated the software landscape, to the point that it is today considered as the only possible model by many (knowledgeable) people. Only recently has the software industry considered free software as an option again.

When IBM and others sold the first large-scale commercial computers, in the 1960s, they came with some software which was free (libre), in the sense that it could be freely shared among users, it came with source code, and it could be improved and modified. In the late 1960s, the situation changed after the ``unbundling'' of IBM software, and in mid-1970s it was usual to find proprietary software, in the sense that users were not allowed to redistribute it, that source code was not available, and that users could not modify the programs.

In late 1970s and early 1980s, two different groups were establishing the roots of the current open source software movement:

• On the US East coast, Richard Stallman, formerly a programmer at the MIT AI Lab, resigned, and launched the GNU Project [26] and the Free Software Foundation. The ultimate goal of the GNU Project was to build a free operating system, and Richard started by coding some programming tools (a compiler, an editor, etc.). As a legal tool, the GNU General Public License (GPL) was designed not only to ensure that the software produced by GNU will remain free, but to promote the production of more and more free software. On the philosophical side, Richard Stallman also wrote the GNU Manifesto,
  
  stating that availability of source code and freedom to redistribute and modify software are fundamental rights.
  
  
• On the US West coast, the Computer Science Research Group (CSRG) of the University of California at Berkeley was improving the Unix system, and building lots of applications which quickly become ``BSD Unix''. These efforts were funded mainly by DARPA contracts, and a dense network of Unix hackers around the world helped to debug, maintain and improve the system. During many time that software was not redistributed outside the community of holders of a Unix AT&T licence. But in the late 1980s, it was finally distributed under the ``BSD licence'', one of the first open source licences. Unfortunately, at that time every user of BSD Unix also needed an AT&T Unix licence, since some parts of the kernel and several important utilities, which were needed for a usable system, were still proprietary.

Other remarkable open source project of that time is TeX (a typesetting system, by Donald Knuth), which formed around it a strong community which still exists today.

During the 1980s and early 1990s, open source software continued its development, initially in several relatively isolated groups. USENET and the Internet helped to coordinate transnational efforts, and to build up strong user communities. Slowly, much of the software already developed was integrated, merging the work of many of these groups. As a result of this integration, complete environments could be built on top of Unix using open source software. In many cases, sysadmins even replaced the standard tools with GNU programs. At that time, many applications were already the best ones in their field (Unix utilities, compilers, etc.). Especially interesting is the case of the X Window System, which was one of the first cases of open source software funded by a consortium of companies.

During 1991-1992, the whole landscape of open source software, and of software development in general, was ready to change. Two very exciting events were taking place, although in different communities:

• In California, Bill Jolitz was implementing the missing portions to complete the Net/2 distribution, until it was ready to run on i386-class machines. Net/2 was the result of the effort of the CSRG to make an unencumbered version of BSD Unix (free of AT&T copyrighted code). Bill called his work 386BSD, and it quickly became appreciated within the BSD and Unix communities. It included not only a kernel, but also many utilities, making a complete operating system.
  
  The work was covered by the BSD licence, which also made it a completely free software platform. It also included free software under other licenses (like for instance the GNU compiler).
  
  

• In Finland, Linus Torvalds, a student of computer science, unhappy with Tanenbaum's Minix, ⁵ was implementing the first versions of the Linux kernel. Soon, many people were collaborating to make that kernel more and more usable, and adding many utilities to complete GNU/Linux⁶, a real operating system. The Linux kernel, and the GNU applications used on top of it are covered by GPL.

In 1993, both GNU/Linux and 386BSD were reasonably stable platforms. Since then, 386BSD has evolved into a family of BSD based operating systems (NetBSD, FreeBSD, and OpenBSD), while the Linux kernel is healthy evolving and being used in many GNU/Linux distributions (Slackware, Debian, Red Hat, Suse, Mandrake, and many more).

During the 1990s, many open source projects have produced a good quantity of useful (and usually high-quality) software. Some of them (chosen with no special reason in mind) are Apache (widely used as a WWW server), Perl (an interpreted language with lots of libraries), XFree86 (the most widely used X11 implementation for PC-based machines), GNOME and KDE (both providing a consistent set of libraries and applications to present the casual user with an easy to use and friendly desktop environment), Mozilla (the free software project funded by Netscape to build a WWW browser), etc. Of all these projects, GNOME and KDE are especially important, because they address usability by non-technical people. Their results are already visible and of good quality, finally allowing everybody to benefit from open source software. The software being produced by these projects dispels the common myth that open source software is mainly focused on server and developer-oriented systems. In fact, both projects are currently producing lots of desktop personal productivity applications.

The late 1990s are very exciting times with respect to open source software. Open source systems based on GNU/Linux or *BSD are gaining public acceptance, and have become a real alternative to proprietary systems, competing head to head with the market leaders (like Windows NT in servers). In many niches, the best choice is already open source (an outstanding case is Apache as Web server, with a market share consistently over 50%).

The announce of the liberation of Netscape Communicator, in 1998, was the starting point of a rush of many big companies to understand open source software. Apple, Corel and IBM, for instance, are trying different approaches to use, promotion or development of open source software. Many companies of all sizes (from the small startup composed of a couple of programmers to the recently public Red Hat) are exploring new economic models to succeed in the competitive software market. The media has also started to give attention to the formerly marginal open source software movement, which is now composed not only of individuals and non-profit organizations, but also of small and medium companies.

Looking at all these events, the following question easily arises: Are we at the beginning of a new model of the software industry? This is a question which is difficult to answer, since there is no known and reliable method for looking into the future. However, through this document, we hope to provide readers with some information which can be useful can use to reach their own answer.

Footnotes

... proprietary⁴

Through this document, the term proprietary software will be used to denote all non-free software. This is the usual term for that concept in the free software community.

... Minix,⁵

Minix is an operating system designed to be useful for learning about the implementation of operating systems, and was at that time partially described in Tanenbaum's classic book ``Operating Systems''.

... GNU/Linux⁶

Throughout this paper, we will use the term `GNU/Linux' to refer to the whole operating system, and `Linux' to refer to the kernel. Although we know that many people use `Linux' for both concepts, we feel more comfortable acknowledging the job of both the team who built the Linux kernel and the people who contributed to the GNU project. Both made feasible the existence of the whole operating system.