Linus Torvalds released the Linux operating system from his college dorm room in Finland in 1991. Since then, the software has taken over the world. Huge swathes of the internet - including the servers of Google, Amazon and Facebook - run on Linux.
More than a billion Android smartphones and tablets run on Linux, as do billions upon billions of everything from appliances and medical devices right on up to cars and rockets.
Linux is open-source, letting people change it as they please, but Torvalds remains the lone official arbiter of the software, guiding how Linux evolves.
What's more, Torvalds may be the most influential individual economic force of the past 20 years. He didn't invent open-source software, but through Linux he unleashed its full power. Torvalds has proven that open-source software can be quicker to build, better, and more popular than proprietary products. The result is that open-source software has overtaken proprietary code as the standard for new products, and the price of software overall has plummeted. Torvalds has, in effect, been as instrumental in retooling the production lines of the modern economy as Henry Ford was 100 years earlier.
It's absurd that so much power has collected in one man. In the early days of Linux, proprietary software giants such as IBM and Microsoft scoffed at the idea of this man and his hobbyist code accomplishing much. As Linux's popularity soared, their tune changed. IBM and others embraced Linux. Microsoft likened it to cancer and portrayed open-source software as an affront to capitalism. Torvalds was then made out to be the socialist software activist threatening the huge profits of the software industry earned honestly in the US of A.
The truth is that Torvalds has never really been a man of the people. "It's not that you do open-source because it is somehow morally the right thing to do," he says. "It's because it allows you to do a better job. I find people who think open-source is anti-capitalism to be kind of naive and slightly stupid."
Torvalds's attitude and direct language have left him isolated. The proprietary software clan does not care for him. Nor do parts of the open-source clan, who want a leader more willing to spout religious zeal. Torvalds also has a tendency to be nasty to the followers he does have, peppering Linux forums with foul language and reprimands. "SHUT THE F--- UP!" he wrote to a Linux developer in 2013. "Fix your f---ing 'compliance tool,' because it is obviously broken. And fix your approach to kernel programming." The general reaction to this was: "There goes Linus again."
"Everyone is much better off knowing how I feel about things," Torvalds says. "I don't actually tell people what to do. I tell them what not to do. When people don't take responsibility for their bugs, then I make it clear that is not acceptable. I use colorful language. I am not sorry for doing that. I am sorry people take my colorful language out of a bigger context."
It's weird that a person who can come off as a grouch has managed to be such an effective dictator. Linux was once 10,000 lines of code and required part-time tending. It's now 19m lines of code, and in an average year, more than 3,000 people will offer at least one change for the heart of Linux.
The change could be as simple as fixing a spelling error or something more complex, such as code for a specialised supercomputing operation. There are around 700 "maintainers," who first gather and peruse those changes and move them on to 130 "subsystem maintainers," who discuss the software on mailing lists. Greg Kroah-Hartman, who is Torvalds's right-hand man, can receive upwards of 1,000 emails a day from Linux developers debating the merits of the various tweaks. After all this discussion is done and the code is tested and perfected, Torvalds is finally notified that someone would like to make a change to Linux.
Torvalds knows Linux so well that most of the changes - aka patches -are evaluated in a flash.
"I just look at something and think, 'No, it can't work' because that comes with spending so much time with the code. It's like looking at a book, and you don't see the individual letters or words but see sentences." When Torvalds goes to test big changes, he might spend 10 to 25 minutes verifying that everything works as expected; during busy periods he might evaluate 30 changes a day. Usually things work fine. "I seldom have to get involved at a low level any more," he says. "Most of the code I get is written by tens of people over some time."
Torvalds used to attend things like the Linux User Group meetings that take place in almost every major city. He doesn't do that anymore, either. "Once it got out that he went to the meetings in Portland, it became a problem," says Kroah-Hartman.
"One time somebody sat across from him and stared at him for an hour without ever saying anything." So Torvalds remains locked in his home office, amid dozens and dozens of stuffed Tux penguins.
As Torvalds has pulled back, Kroah-Hartman and a couple of other lieutenants have come to the fore. They've built strong reputations as trusted arbiters of code. They're also just as responsive as Torvalds used to be, keeping the Linux developers interested and enthused. This is why Torvalds now thinks it would be all right if he died. There are Deciders in waiting. "The technical know-how these days is less," Torvalds says. "It's more about being trusted and being available. Greg is the obvious number two. He could take it up, and then there are a couple of other people."
Bring up his influence on the world economy, and Torvalds will shift the discussion to something like the lack of good, crusty bread in the US.
If you keep nudging him, he'll at least open up about what open-source means to the world. "You are seeing now that the software industry is a much healthier place," he says.
"It's harder to make a breakout thing that no one else can replicate. For software that everyone ends up wanting, open-source is a good option. Software is infrastructure."