EDITOR DIRK RIEHLE Friedrich Alexander-University of Erlangen Nürnberg; OPEN SOURCE EXPANDED [email protected]

A Brief History of Free, Open Source

Software and Its computers, with IBM being, by a large margin, the market leader. For all of them, was just a companion to hardware: as long as Communities you paid for maintenance, you had access to the software catalog of the Jesus M. Gonzalez-Barahona, Universidad Rey Juan Carlos manufacturer. User groups, such as SHARE (IBM) and the DECUS [Digital Free, open source software (FOSS) has a long history, beginning with Equipment Corp. (DEC)] favored soft- ware sharing. To some extent, prior the origins of software itself, when the terms and open to 1970, software was just an add-on source software were not yet defined. Learning about the milestones to hardware, not something consid- ered valuable in itself. of this history may help to understand FOSS today. The situation changed in 1969, when IBM announced the unbun- dling of software: part of its catalog he concept of “free software” (with free as in free- was to be sold separately. From that moment on, users had dom) dates from the early 1980s. The term open to purchase some of the software they needed. Various source is much younger, from the late 1990s. companies began to flourish with a business model based But before free and open source software (FOSS) on producing software to be run on hardware sold by oth- Texisted as such, some programs were paving the way. In ers. This kicked off the software market and, with it, the fact, until the late 1960s, most software worked as FOSS: change of software’s status. Vendors implemented techni- it was shared with relative ease between people who took cal and legal means to limit sharing, modifying, and even care of computers. Only a few companies manufactured studying programs. During the mid-1970s, proprietary (non-FOSS) software was already the norm. However, by the early 1980s, some programs were distributed in ways Digital Object Identifier 10.1109/MC.2020.3041887 Date of current version: 11 February 2021 similar to what we now consider FOSS, among them, SPICE

COMPUTER 0018-9162/21©2021IEEE PUBLISHED BY THE IEEE COMPUTER SOCIETY FEBRUARY 2021 75 OPEN SOURCE EXPANDED

Debugger), and several utilities. In 1985, Stallman founded the Free Soft- FROM THE EDITOR ware Foundation to support and foster Welcome back, and welcome to a new thematic arc in our “Open Source the GNU Project and free software Expanded” column! Until now, we have looked only at using open source in general. software, mostly from a company perspective. Now, we will examine how He also established the philosoph- community open source projects work, collaborating across volunteers and ical principles of free software, in- companies. I’m very happy to have convinced Jesus M. Gonzalez-Barahona, a long-time open source researcher and enthusiast, to write this opening article cluding the definition of the concept. about the history of open source and its communities. He will take us through This characterization was based on what are, by now, several decades of open source history. Enjoy! And, as al- “four freedoms” for any user of a free ways, happy open hacking, everyone, and be safe! — Dirk Riehle software program: use, study and mod- ify, redistribute copies, and distribute modifications. The GNU Project pro- duced licenses for the software it was (Simulation Program with Integrated those parties formed a community releasing. Those licenses were the legal Circuit Emphasis), TeX, and Unix. composed mainly of academic institu- projection of the four freedoms. In 1989, In 1973, SPICE and its source code tions and research centers that worked they were unified in the GNU General were placed in the by in a similar way to later FOSS groups. Public License (GPL), the first of one of their author, Donald O. Pederson. The Its members shared and improved the the most successful families of FOSS program was a tool for learning inte- code, and the Computer Systems Re- licenses. The GPL was a clever hack: it grated circuit (IC) design, and it was search Group (CSRG) at the University protected software users’ freedoms by quickly adopted by several universi- of California, Berkeley, began produc- using copyright law. ties. With time, SPICE and its deriva- ing its own Unix distributions. This The GNU Project’s work was struc- tives evolved into the industry’s pre- was a keystone of the emergence of tured in small teams of volunteers who ferred tools to design ICs, becoming FOSS during the late 1980s. Earlier in produced different pieces of software, according to a carefully designed plan. Around 1990, the project had almost completed an operating system. How- Until the late 1960s, most software worked as ever, its tools were always running on FOSS: it was shared with relative ease between top of proprietary or non-free kernels be- people who took care of computers. cause it still lacked their own versions. Meanwhile, during the 1980s, the CSRG lead a large community that was the de facto standard. It was the first that decade, these cases provided some busy working on improving Unix, pro- example of how a FOSS-based strategy experience with how FOSS-en- ducing Berkeley Software Distribution could lead to market dominance. abled mechanisms worked. (BSD) Unix. The community included TeX was developed by people from the University of California in 1978, during a sabbatical, as a typeset- THE 1980S: GNU, BERKELEY at Berkeley and the University of Cali- ting system to produce quality output. SOFTWARE DISTRIBUTION, fornia at Los Angeles to MIT; Stanford; Knuth intended to use it for typesetting AND THE Carnegie Mellon; and others. There his own books but distributed it as source In 1983, Richard Stallman announced were industry members, too, notably code as well, through an authorization the GNU Project, with the aim of pro- AT&T and Bolt, Beranek, and Newman, that today would be considered quite ducing a Unix-like system composed the company producing the first imple- similar to a FOSS license. Since then, TeX only of free software. Stallman, who mentations of Internet protocols. The ef- has become the standard in scientific was by then a programmer at the Mas- forts were funded mainly by R&D grants typesetting, and it is still popular. sachusetts Institute of Technology from the U.S. government via DARPA. Unix was created by Thompson, (MIT) Artificial Intelligence Lab, quit With time, BSD Unix had less and Ritchie, and others at AT&T Bell Labs, his job to ensure that he had full own- less code from the original AT&T Unix starting in 1972. Since 1973, Unix has ership of the software he wrote. The and more and more code produced by been distributed to many universities, project began with an editor (Emacs) its contributors. The original AT&T with a license permitting academic and some other tools and quickly code was covered by the Unix license, use. The software could not be dis- produced various key components. but not all the new code was. In 1989, seminated beyond the signatories of By 1987, it delivered a compiler (GNU the code not covered by the Unix license the license, but during the late 1970s, Compiler Collection), a debugger (GNU was offered as Networking Release 1

76 COMPUTER WWW.COMPUTER.ORG/COMPUTER (Net/1) under the BSD license, which quickly became a mixture of people led the development of some of those was free. Net/1 still lacked some mod- working on their own time as volun- tools, such as the GNU debugger, as- ules to be a complete, working operat- teers collaborating with people hired sembler, and linker, all of which were ing system. At that time, several com- to assist them. In the beginning, hired fundamental to the GNU Project and panies were using BSD Unix (including developers mainly worked at univer- the FOSS community at large. This Unix licensed code) as the basis of their sities, such as the teams at the CSRG not only helped to bring stability and operating systems, and some of them and other BSD Unix contributors. In resources to the project but it showed were contributing to BSD with ports to many cases, their funding came from how companies could profit and grow specific hardware, new applications, R&D institutions, especially DARPA. from maintaining and building FOSS and bug fixes. The effort of incorporat- But companies were involved in two components by becoming a focal point ing all this into the BSD code base was major ways: by directly funding FOSS of expertise. The fact that Cygnus was coordinated by the CSRG. projects and by making their employ- directly involved in the production Another remarkable project of the ees work on FOSS projects. and maintenance of FOSS projects late 1980s was the , The most prominent case of a project signals how interesting such efforts which produced a platform-indepen- funded by companies was X Window, were to many companies. Those orga- dent graphics system incorporating developed at MIT, which jointly funded nizations were using GNU tools in pro- a protocol that enabled applications the work with DEC and IBM. This was duction environments, and they were to use a graphics terminal, even re- one of the first projects to evolve from ready to pay Cygnus for support and motely. X Window was released in (several licenses new functionality. 1986 under the MIT license, which was of X Window were sold) to being later Another remarkable case of a com- also free and, in many aspects, similar released as FOSS in 1986. The project pany with a business model centered on to the BSD license. was so successful that several compa- FOSS was Aladdin Software, although During the 1970s and early 1980s, nies used it as the basis of their GUIs, at for a different reason. Since 1986, another development community was creating software under similar models: the Internet (at first, the Ar- panet) community. Since the early As the Internet became popular at universities, its 1970s, it had collaboratively been pro- tools and protocols became fundamental for the ducing requests for comments (RFCs) development of communities supporting (specifications of standards) as open free software. documents that were accessible to any- one. The protocols were complemented by reference applications, which were a moment when GUIs were a key char- Aladdin had developed , a designed to be easily portable to man- acteristic of workstations. Several of PostScript interpreter, and released it ufacturers’ systems. During the 1980s, these companies assigned large teams under the GNU Project as GNU Ghost- the community developing Internet to port X Windows to their systems and script. But the company used a dual Protocols and applications was closely to build new applications for it. Some of licensing model, maintaining its own related to the Unix BSD group since the resulting software was contributed version, Aladdin Ghostscript, under a BSD Unix was the usual target for de- back to the FOSS project, showing the non-FOSS license. With this model, it velopments. Later, as the Internet be- benefits of sharing upstream. In 1988, was exploring how dual licensing could came popular at universities, its tools X Window was so important to nu- prevent its competition from using the and protocols became fundamental merous vendors that they decided they latest features in the software while for the development of communities needed to formalize a neutral point to maintaining a FOSS version that sus- supporting free software projects. In drive its evolution, forming the MIT X tained the popularity of the program. an epoch when remote coordination Consortium. This was the first case of At the end of the 1980s, FOSS was still usually done via phone and competing companies establishing a communities were complex in many postal mail, free software communi- nonprofit to provide stewardship of a ways, with people and companies ties were already communicating via FOSS project. collaborating by sharing software email lists and sharing software elec- The best-known case of a com- and, indirectly or directly, resources. tronically via FTP or its poor-man ver- pany assigning employees to work on They were exploring several sustain- sion, the Unix-to-Unix copy network FOSS projects at that time was Cyg- ability models: public funding (via (UUCPnet). nus Support, which was founded in R&D grants), donations collected Those were also years of testing 1989 to commercially sustain some via nonprofits, direct funding from sustainability models for FOSS. Projects of the GNU tools. Its employees had companies, the direct involvement of

FEBRUARY 2021 77 OPEN SOURCE EXPANDED

companies via neutral consortiums, from the beginning as such, BSD had people involved in FOSS development pure volunteer work, and combina- steering committees, X Window orga- and maintenance kept growing. tions thereof. They set up a legal in- nized the MIT X Consortium, and so on. It was during the mid-1990s that the frastructure centered on the two fam- Internet evolved from an academic cu- ilies of FOSS licenses that are still in THE EARLY 1990S: , riosity to a mass market service, with use today: those based on the princi- *BSD, AND COMPANY the web becoming the primary mech- ples of the GPL and those established During the early 1990s, developments anism for accessing information and, on the principles of the BSD and MIT started during the previous decade later, digital services. The importance licenses. They had a solid philosoph- converged in the first complete sys- of FOSS components for Internet infra- ical basis, formalized in several doc- tems composed only of FOSS compo- structure was evident, being one of the uments that were widely known in nents: *BSD and Linux. In the BSD Unix enablers of the expansion of this tech- their communities. And they were camp, the CSRG had reimplemented nology. Most of the implementations of Internet Protocols were either FOSS or derived from FOSS projects. Many of the most popular services were im- FOSS emerged as a strategic tool that could be plemented as FOSS, such as Sendmail harnessed to build neutral consortiums, where and NCSA (and later Apache), competitors could collaborate. which were dominant among email and HTTP servers, respectively. A new kind of FOSS-related com- producing software of interest to in- most of the missing components to pany appeared that was linked to Li- dividuals and companies, both for produce a complete Unix-like system nux-based distributions. In fact, many ethical and practical reasons. under the BSD license. This was dis- of the major Linux-based distributions Companies were also learning how tributed as Net/2. In 1992, 386BSD were promoted by companies: Red Hat, to benefit from FOSS development. was released with an implementation SuSe, Mandrake, and others. They all Some small companies were trying of the small pieces that Net/2 needed, began by marketing a Linux-based pure FOSS business models. Others thus resulting in the first full FOSS sys- distribution and expanded to offer a used FOSS as a viable model. And FOSS tem. NetBSD, FreeBSD, and OpenBSD mixture of services, from training to emerged as a strategic tool that could were later evolutions. support, that were, in general, loosely be harnessed to build neutral consor- Meanwhile, in 1991, Linus Torvalds based on their distribution and, to some tiums, where competitors could col- announced his project for writing an extent, their brand. Other companies, laborate to produce software that they operating system kernel, which would such as VA Linux, joined this growing all found interesting. Some companies soon be named Linux. It quickly gained market of FOSS-based solutions. noticed how existing FOSS compo- traction and contributions from other nents could be employed to build large developers. In 1994, Torvalds released THE LATE 1990S AND parts of complex systems, enabling Linux 1.0, the first “stable” version, THE 2000S: THE AGE them to leverage their own develop- although the software was already OF FOUNDATIONS AND ments at a fraction of the cost of creat- usable in 1993, and, in some respects, CORPORATIONS ing the modules themselves. in 1992. Many tools, including from In 1998, Netscape announced that its By this time, FOSS development GNU and BSD, were ported to it, and flagship application, Netscape Com- communities used digital means for different groups started to produce municator, was to be released as FOSS. communication (mailing lists, Usenet Linux-based distributions (such as Netscape Communicator was one of groups, FTP servers, and UUCPnet), Slackware, , or Red Hat). the two web browsers that dominated enabling them to work in large, geo- Around 1993, *BSD and Linux-based the market (the other was graphically distributed networks. They distributions were perfectly usable, Internet Explorer), and Netscape was explored organizational mechanisms complete operating systems that could one of the most prominent compa- that included, in some cases, appointed be installed on PCs. With time, Linux nies of the new Internet era. Because figures (such as GNU “maintainers,” became the most popular, and during of this, the announcement received who acted as leaders of their develop- most of the 1990s, many cohorts of plenty of attention from the media. To ment communities) and de facto coor- young developers, including students some extent, this event signaled that dinators (as CSRG personnel were for at numerous universities, were ex- FOSS was becoming something real for BSD to some extent). Formal organi- posed to it. New FOSS projects, small companies, something that they could zations for stewardship projects were and large, launched in many places use as a part of their strategy. In prepa- already common: GNU was conceived and domains, and the number of ration for the announcement, the term

78 COMPUTER WWW.COMPUTER.ORG/COMPUTER open source software was coined as an FOSS desktop application. Partly as a and related tools, which then extended alternative for free software, and the reaction to KDE using some non-FOSS to many other domains. In 2004, the was formed. components, the GNU Network Object Foundation was established At about the same time, large FOSS Model Environment (GNOME) was an- as a neutral nonprofit to steward the communities emerged. The GNU Proj- nounced in 1997, with similar objec- project. It was formed by companies ect included a growing number of tives. Soon, hundreds of developers providing financial resources and by tools and members. People were also joined both of them. Various compa- Eclipse developers. They all partici- joining the Free Software Founda- nies began hiring developers to work pated in strategic decisions. tion. New projects were bootstrapped. on the projects because they wanted to Debian was one of them. In 1993, it was drive the evolution of certain applica- established to maintain the Debian tions. This was the case, for example, hese software development Linux-based distribution, and it was with SuSe and Red Hat: the desktop communities and their cor- soon joined by tens, and eventually environment of their Linux-based dis- responding nonprofits have hundreds, of developers. Debian was tributions was to be improved. Some Texplored different relationship mod- a community of individuals, where others, such as Helix Code and , els between developers and the com- companies didn’t have a role. In this were small start-ups funded to develop panies with interests in their proj- respect, it followed the GNU tradi- specific applications. ects. From the very developer-centric tion, although from the beginning, GNOME and KDE established non- Debian and Apache to those with sig- its governing rules, which were ex- profits to support the projects, and nificant direct company participation plicit, led to a much more horizon- both found ways to let companies (KDE, GNOME, and Eclipse), from those tal organization. participate directly. KDE’s nonprofit originated by companies ( Another community of develop- was formed in 1997, and the GNOME and Eclipse) to those with origins in ers was Apache, first built around Foundation was incorporated in 2000. individual developers (almost all the the Apache HTTP server and then ex- Using different mechanisms, compa- others mentioned previously), from panded with other FOSS components. nies that contributed significant re- those with clear and detailed gover- In 1993, the project was born as the sources participated in the projects’ nance and participation rules (such Apache Group, which expanded and decision making, and combined with as Apache, Debian, KDE, GNOME, and formed the Apache Software Founda- the influence they obtained by hiring Eclipse) to those based more on prac- tion in 1999. This, too, was a commu- developers, they had a real impact on tices and the personal charisma of nity of individuals, although many of the initiatives. GNOME and KDE were some individuals (GNU and Linux), its members were hired by companies. the most prominent organizations ex- they all have produced FOSS compo- However, Apache tried to remain neu- ploring the path toward communities nents of interest. They have proved to tral with respect to companies, follow- of companies, which had begun with be sustainable, remained attractive to ing a spirit that resembled Debian’s. the MIT X Consortium. developers (either hired or volunteer), The group of developers producing Netscape launched Mozilla to pro- and devised their own approaches to the Linux kernel was one of the major duce the FOSS version of Netscape structuring productive FOSS com- software development communities Communicator. But Netscape’s new munities. The current landscape of formed during the 1990s. From its be- owner, AOL Time Warner, lost inter- FOSS development is the result of this ginning, the project was very clearly est in the initiative. In 2003, the Mo- history. There has been progress, and directed by Torvalds, with only a few zilla Foundation was formed to legally there have been contradictions. There formal governing rules. Although com- steward the project, independently has been collaboration but also fierce panies had no direct role, they hired from AOL. From then on, the Mozilla competition between models, aims, many Linux developers, who often had Foundation searched for lines of rev- and mechanisms. Today’s FOSS is the clear interests in the system’s develop- enue, which it found in agreements product of it all. ment. In 2000, the with companies, notably Google, that was formed to organize contributions were interested in its flagship pro- from these companies and support the gram, Firefox. Thanks to this revenue, project although, in general, technical Mozilla hired a large team of develop- decisions remained relatively separate. ers, and it also built a large community JESUS M. GONZALEZ-BARAHONA Later, the Linux Foundation extended of volunteer supporters. is with the Universidad Rey Juan the model to many other projects that In 2001, the Eclipse project was cre- Carlos, Fuenlabrada, 28943, Spain. came under its umbrella. ated by IBM and supported by a group of Contact him at jesus.gonzalez In 1996, the Kool Desktop Envi- software companies to produce a FOSS [email protected]. ronment (KDE) was born to develop a integrated development environment

FEBRUARY 2021 79