In the late 1970s the programming community faced an unexpected threat as corporations began to monetise software that had previously been shared for free. Many talented engineers eventually capitulated in the uneven contest between enthusiasts and tech giants—but not hacker Richard Stallman.
How he managed to spark a revolution in software freedom is the subject of a new instalment in the Silicon Tanks series, in which ForkLog revisits the most influential visionaries in IT.
Hackers, corporations and a faulty printer
Richard Matthew Stallman, who gained early notoriety in the hacker community as RMS, was born on March 16, 1953, in New York. He graduated from Harvard University in 1974 and entered graduate school at the Massachusetts Institute of Technology (MIT). He soon left the programme, but kept his job as a programmer at MIT’s Laboratory for Computer Science and Artificial Intelligence, where he had worked since 1971.
At the time Stallman joined a community whose members actively shared experience and software needed to create new programs. The free exchange of information became more difficult with the advent of commercial software.
In the early 1980s Digital Equipment Corporation stopped supplying hardware for the PDP-10 machines used by the lab’s team. And in 1981 almost all of Stallman’s colleagues left for Symbolics.
Computers of the day had their own operating systems, but none was “free”. At the new companies, employees were required to sign non-disclosure agreements before receiving executables. Participation in the hacker community was forbidden.
The last straw for Stallman was a faulty printer he used in the lab. When he requested the machine’s source code to upgrade it, he was refused.
This seemingly minor incident led RMS to conceive a wholly new paradigm for sharing information. On September 27, 1983, Stallman announced the start of development of a free, Unix-like and completely free operating system, GNU. In January 1984 he left MIT and devoted himself entirely to the ambitious project.
From GNU to GNU/Linux
The project name followed hacker tradition—as a recursive acronym for “GNU’s Not Unix”. The step was needed to head off potential claims of authorship.
In 1985, to support GNU and the free-software movement, Stallman founded the Free Software Foundation (FSF). That same year the text editor GNU Emacs appeared, displaying changes in real time—a technical breakthrough at the time. It was based on the commercial programme Gosling Emacs, from which Stallman stripped the proprietary taint.
Control over modified versions was not entirely free. Stallman consulted intellectual-property lawyers Mark Fischer and Jerry Cohen. They helped find a loophole that allowed replacing the word Emacs with “software” in documents and using copyright as the basis for a new kind of licence.
The software proved popular and was distributed by post on physical media for $150. Thus GNU Emacs became the first program to receive the copyleft GNU GPL licence.
The next milestone was the development of the GNU C Compiler (GCC) in 1987. GCC was not only free but outperformed many contemporaries, which ensured rapid adoption.
By 1990 the GNU system was almost complete; the only major missing component was the kernel. That problem remains unresolved to this day. When Linus Torvalds introduced Linux in 1991, the GNU team moved to the Finnish developer’s operating system.
“We call this version of the system ‘GNU/Linux’ to show that it is assembled from the GNU system with Linux as the kernel. Please do not get into the habit of calling the entire system Linux, because that means crediting our work to someone else. Please mention us equally, too,” — ask at the FSF.
Copyleft
Copyleft is a concept that makes a program or work of art free. Its observance requires that all modified and extended versions also remain free.
In the original description of GNU licences, “freedom” does not mean devaluing the product, but its open transfer along the entire chain of users. Selling copies of software does not contradict Stallman’s concept; on the contrary, it helps a project exist and develop.
“[Copyleft] relies on copyright law but turns it around, turning it into the opposite of its usual purpose: instead of a means of restricting a program, it becomes a means of preserving its freedom,” — noted RMS, describing the aims of copyleft.
Stallman also defined four key freedoms of software:
- to run the program for any purpose;
- to modify the code to suit your needs, with access to the source;
- to distribute copies—free of charge or for money;
- to improve and promote versions of the software for the benefit of the community.
However, renouncing copyright as the simplest way to place a work in the public domain does not solve the problem of an intermediary’s proprietary instincts. Any participant could appropriate and commercialise the product by making minimal changes.
“Our goal is to give all users the freedom to distribute and modify GNU software. If intermediaries could deprive a program of that freedom, our code might ‘have many users’, but it would not give them freedom. Therefore, instead of putting the software into the public domain, we apply copyleft,” the GNU description says.
Copyleft today
In 1998 part of the GNU community split off and stopped using the term “free software”. Instead, developers began using the phrase “open-source software”. Open source grants full rights to use, modify and distribute the product.
In a 2007 essay Richard Stallman commented on the split:
“Some of those who supported the term ‘open source software’ sought to avoid the confusion between the words ‘free’ and ‘gratis’—that was a perfectly reasonable goal. However, others seemed to want to push aside the ethical and social values implied by the expression ‘free software’ and instead appeal to executives and business users, many of whom adhere to an ideology that puts profit above freedom, above community, above principles.”
Today, copyleft generally includes the following main forms of licences:
- strong copyleft. Requires that all derivative software be distributed under the same licence. GPLv2 and GPLv3 imply that any modifications and derivatives must remain GPL. The CC BY-SA (Creative Commons Attribution-ShareAlike) licence is intended not for code but for texts, images and other content;
- weak copyleft. Less stringent: copyleft applies only to part of the code, not the whole program. LGPL (Lesser GPL) is usually applied to libraries. MPL (Mozilla Public License) requires that modified files remain open, but the rest of the project’s code may be licensed differently. EPL (Eclipse Public License) is similar to MPL and used in the Eclipse ecosystem;
- Affero copyleft. AGPL (Affero GPL) is a strengthened variant of GPLv3 that also applies to software provided as a web service over a network. This is a special case of “strong copyleft”. If a program runs on a server and is provided as a service, its sources must also be available to users.
In the 1990s Stallman largely stopped writing code and focused on promoting the idea of copyleft. In 2021 he returned to the FSF board of directors, which he had left two years earlier amid a scandal over public statements that some in the community considered offensive. In 2023, at a conference marking GNU’s 40th anniversary, the project’s founder announced that he had been diagnosed with blood cancer.
Many popular projects are now distributed under the GNU GPL, including WordPress, phpBB, MediaWiki, GNU Mailman, Audacity, MPlayer, GPL Ghostscript, GIMP, Inkscape, and the games Battle for Wesnoth, OpenRA and Freeciv. And in July 2025 Ethereum’s founder Vitalik Buterin urged the crypto community to switch to copyleft.