How Open Source Changed the World

In the previous article, What Is a Hacker, I mentioned something the hacker clubs at MIT used to say back in the 1960s: “Information wants to be free.” The idea is that you don’t keep the principles and code you’ve figured out to yourself. Instead, you release them so everyone can read and improve them.

If that idea had stayed nothing more than a slogan, there would be no reason to write this article. But that spirit grew up under the name open source, and today nearly every service you use runs on top of it. Among smartphones, websites, search engines, and messengers, it’s harder to find one that doesn’t use even a single line of open source. In this article, I’ll explain in plain terms what open source is and how it came to be the foundation of modern IT.

What Is Open Source #

Open source refers to software whose source code is made public. Source code here means the blueprint of a program in a form people can read and write.

Most commercial software doesn’t reveal this blueprint. We only receive the finished product and use it, with no way to know what’s happening inside. Open source does the opposite: it opens the entire blueprint. Anyone can look into the code, fix what they don’t like, and redistribute their changes to others.

These three things, the ability to read, modify, and redistribute, are the heart of open source. It doesn’t simply mean “free of charge.” To use a car analogy, free software is a car that comes with free gas, while open source is a car that lets you pop the hood, take apart the engine yourself, and swap out parts.

It Started with the Free Software Movement #

The roots of open source trace back to a programmer named Richard Stallman. In the early 1980s, software companies began locking away their source code. Stallman pushed back against this trend. He saw it as unjust that users were being stripped of the freedom to read and modify code.

So in 1983, Stallman started the GNU project. The plan was to build, from scratch, an operating system that anyone could freely use and modify. In 1985, he founded the Free Software Foundation.

Another important contribution was the license. The GPL (GNU General Public License), which he finalized in 1989, embodied a peculiar concept called copyleft. It sounds like a pun that flips “copyright” on its head, but the idea behind it is serious. “You’re free to use this code. But anything you build with it must be released just as freely.” It was freedom that enforced freedom.

Linux Fills the Missing Piece #

The GNU project had built almost every part of an operating system, but the kernel — the innermost core that talks directly to the hardware — was never finished.

The person who filled that gap was a Finnish university student named Linus Torvalds. In 1991, he released the operating system kernel he had built to the internet. This was Linux. When GNU’s parts and the Linux kernel came together, a fully free operating system was finally complete.

Interestingly, this movement was first called “free software.” But because the English word free means both “freedom” and “no cost,” companies often took it as a conversation about money. So in February 1998, at a meeting that included Christine Peterson and others, the new name “open source” was proposed, and the term quickly caught on. It was a name that put the openness of the code, rather than the price, front and center.

GPL and MIT: Two Kinds of Promise #

Not all open source follows the same rules. What’s permitted varies by license. Let’s take a light look at the two broad branches.

One side is the GPL family we saw earlier. Because it’s copyleft, if you take this code and modify it, you have to release your modified result just as openly. It’s a way of obligating each person to pass freedom on to the next.

The other side consists of permissive licenses like MIT or Apache. These are far looser. You can take the code, modify it, and sell it as a commercial product without releasing it, as long as you credit the source. Since the burden on companies is light, many projects choose this route these days.

It is not so much that one side is right; they simply have different goals. GPL values spreading freedom, while the MIT family values being adopted as widely as possible.

The World Runs on Open Source #

The result of this movement can be summed up in a single sentence: today, nearly every service runs on open source.

The Android smartphone in your hand is built on the Linux kernel. A large share of the websites we visit run on open source web servers. Python and JavaScript, the first languages most people meet when learning to program, are themselves enormous open source ecosystems. Even Google’s Chrome browser is built on top of an open source project called Chromium.

Even the tools developers use to manage their code are open source. Linus Torvalds didn’t just create Linux; he also created Git, which tracks the history of code changes. GitHub, the service where developers around the world upload code and collaborate, is built right on top of Git.

To put it a bit dramatically, if open source stopped, a large part of the internet would stop with it. It’s simply a foundation that stays out of sight.

Not Free, but a Business #

It’s a misconception to think open source runs entirely on volunteer labor. Large companies pour in enormous amounts of staff and money to contribute to open source, and they build businesses on top of it.

A prime example is Red Hat. Linux is something anyone can use for free, yet Red Hat grew its company by selling services: it stabilizes Linux so enterprises can use it with confidence, guarantees security updates, and takes responsibility for support when problems arise. It eventually went so far as to be acquired by IBM for a huge sum.

Even when the software itself is public, there is clear value in operating and supporting it reliably. Giant companies like Google and Microsoft also commit their own staff to help open source projects. Because their own services run on top of it, strengthening the foundation is in their own interest.

Where There Is Light, There Is Shadow #

Open source isn’t all upside. The biggest worry is maintenance.

Saying anyone can use it is, flipped around, also saying no one has to take responsibility for it. It is not uncommon for core projects that the whole world depends on to be maintained, unpaid, by a small handful of volunteers.

The Heartbleed incident that broke out in 2014 laid this problem bare. At the time, about two-thirds of the world’s web servers used encryption software called OpenSSL. Yet the staff maintaining this massive foundation amounted to just a couple of part-time developers, and the donations they received were on the order of a few thousand dollars a year. One small coding mistake spread into a hole that threatened the secrecy of communications worldwide.

The industry was shaken after this incident. The Linux Foundation stepped in and created a group to fund critical infrastructure, and large companies pooled money to hire OpenSSL developers full-time. It was a lesson that the foundation we take for granted may, in fact, be barely held up by someone’s goodwill.

Wrapping Up #

In this article, we looked at what open source is and how it became the foundation of all modern IT, traveling from the GNU project in 1983 through Linux in 1991. We also touched on the two branches of licensing, the relationship with companies, and the shadow side of a few people holding up the foundation.

The hackers’ cry from the previous article, “information wants to be free,” was not a vague ideal. That idea became code, became an operating system, and became the bedrock of the services we use every day. In a sense, one person’s conviction changed the way the world works over the course of decades.

In the next article, I’ll take a closer look at exactly how Git and GitHub, the tools we use to write and manage code together on top of that foundation, transformed the way we collaborate.