Unit 2: The missing piece - A Finnish student (1991)

A hobby that was not going to be a big deal

Throughout the 1980s, the GNU project advanced at a good pace. Stallman and his collaborators built a compiler (GCC), a legendary text editor (Emacs), a command interpreter (Bash) and dozens of tools that form the basic infrastructure of any operating system. They had almost everything. Almost.

They were missing the kernel, the core of the operating system: the piece of software that communicates directly with the hardware, that manages the memory, that decides which program runs and when. Without a kernel, all those magnificent tools were like having the engine, the wheels, the seats and the steering wheel of a car, but not the chassis to mount them on.

The GNU project had its own kernel in development -called Hurd-, but it was progressing with maddening slowness. And then, on 25 August 1991, a 21-year-old student at the University of Helsinki posted a message on the comp.os.minix newsgroup that would become one of the most quoted texts in the history of technology:

"Hello everybody out there using minix - I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. This has been brewing since April, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things)."

"I've currently ported bash(1.08) and gcc(1.40), and things seem to work. This implies that I'll get something practical within a few months, and I'd like to know what features most people would want. Any suggestions are welcome, but I won't promise I'll implement them :-)"

The student's name was Linus Torvalds. The operating system he was building "just as a hobby" and that "was not going to be big or professional" would be called Linux. And it would change the world.

The puzzle is completed

What Torvalds had created was precisely the missing piece. Linux was a kernel: the core that communicated with the hardware and on top of which all the tools the GNU project had built over almost a decade could run. GNU had everything except the kernel. Linux was the kernel that everything else needed. Together, for the first time, they formed a complete and entirely free operating system: GNU/Linux.

Torvalds made a crucial decision: he published Linux under Stallman's GPL licence. This meant the kernel would be free forever, that no one could appropriate it, that any programmer in the world could study its code, improve it and share their improvements.

And that is exactly what happened.

The model that no one believed possible

What happened next defied everything the software industry thought it knew about how programs are built. Thousands of developers from all over the world, most of them not knowing one another, began contributing code to Linux. No one was paying them. There was no master plan and no project director. Quite simply, someone would see a problem, write a solution, submit it, and if it was good, it was incorporated into the kernel. It was pure collaboration on a global scale, coordinated solely by the internet and by peer review.

The sceptics said it could not work. That a serious project needed a company behind it, a budget, a hierarchy. That a bunch of volunteers working for free would never produce anything reliable. History proved them wrong in the most spectacular way possible.

Another gift from Torvalds

In 2005, Torvalds made another contribution that would transform the software industry: he created Git, a distributed version control system. Git allows thousands of people to work simultaneously on the same software project without getting in each other's way, keeping a perfect record of every change, of who made it and why.

Git became the universal standard for software development. On top of it were built platforms such as GitHub and GitLab, which today host practically all of the world's open source code. Every time a programmer anywhere on the planet makes a commit -records a change to their code-, they are using a tool that Linus Torvalds created and gave to the world. Another act of generosity that seemed small at the time and turned out to be immense.