Open Source: The Most Scalable School in History

PRINCIPLE: Real Work Is The Best Teacher

Today's world exists thanks to open source software. It's a simple concept with profound implications: the code is publicly available for anyone to view, use, modify, and distribute. Most licenses ask that if you modify and redistribute the code, those changes must also be made open source. This openness enables collaborative development, shared learning, and continuous improvement by a community of developers.

That simple fact that you can take code and make any change you want has enormous implications. The freedom to modify code means developers can adapt software to their exact requirements. These individualized solutions often address common needs. As developers contribute their improvements back to the main codebase, it evolves: bug fixes accumulate, performance optimizations compound, and architecture improvements scale the entire system. What starts as one developer scratching their own itch becomes a solution that benefits the entire community.

What may have started as the only choice for a person who didn't have the money to pay for proprietary, closed-source software written by a company starts to become a better product than software limited by the investment a single company can make.

Take Linux. In 1991, a Finnish student named Linus Torvalds started an open source project to create a new free operating system kernel. This became the Linux kernel, now with 30 million lines of code that would cost an estimated $15-20 billion to develop from scratch. It's available to anyone, for free, adaptable in any way they like.

Today, this software stack dominates the digital world: it runs every supercomputer on Earth, 96% of the world's servers, 71% of smartphones (Android), and powers the growing universe of smart devices in our homes, from smart TVs to toaster ovens.

The fact that Microsoft - a $3 trillion tech giant - couldn't compete with this free technology reveals something profound. The real breakthrough wasn't just technical, it was social. The open source license, by enabling unlimited collaboration and sharing, created something more powerful than any proprietary model could match.

Today's digital world wouldn't exist without open source software. While companies like Apple, Google, and Facebook present proprietary interfaces - the apps and icons you interact with daily - almost everything under the hood is open source. Your iPhone's beautiful interface may be Apple's, but the web browsers, encryption, databases, and countless other components that make it work are built on free, open source foundations. The modern internet itself is essentially a massive collaboration of open source technologies. An astounding 98% of the world's software has open source components embedded in it.

The Inadvertent Learning Community

Open source communities have inadvertently created the world's largest practice ground for software development. Every bug fix, every feature addition, every code review is a micro-lesson in disguise. Like a child learning to ride a bike who encounters new challenges - a cat darting across their path, a car honking its horn - each pull request presents unique situations that no classroom could simulate. The real work of software development becomes the curriculum itself.

When Endless started focusing on addressing device access in emerging markets, I learned that I needed to have an operating system that could run on the smartphone processor architecture called ARM. We needed many features, starting with a simplified interface that anyone in an emerging market could use like a smartphone, and lots of offline content built into an automatically updating content ecosystem. At the time, I was a Stanford Business School student stepping into the world of Linux operating systems, knowing nothing about them. But I quickly learned how this worked. I could take the code and "fork" it, making any changes I wanted. Then we could "merge" the code back into the mainline codebase. I eventually started getting to know the people at the heart of this community and their learning journey.

As I talked with the engineers, a pattern started to emerge in their stories. It always started with a discovery that Linux was pretty cool. Often it was because it was free. Sometimes it was because they liked the idea of their code being "free as in freedom, not as in beer," as the free software credo goes. "I installed Linux and liked it," they would say.

The next step was always the same: "I issued my first pull request."

That's engineering speak for, "I made my first contribution, a submission of code, with the hope that it would be accepted." It was usually a small bug fix. Sometimes it was a small feature. But the emotion when that pull request was accepted was also always the same: Wow!

Fascination. Little me, I just contributed code to the Linux stack and my contribution, and name, will forever be part of this project. What a mesmerizing feeling - to know that one could add a little piece of light to this incredibly compelling piece of software.

It wasn't always the big Kernel. Often it was a small side project, like the window manager "Compiz", a technology that let your windows bounce like rubber, or have water droplets ripple across the surface of your screen. And then they got hooked. They kept adding stuff.

They would make a second contribution, and then a third. They all took on more ambitious contributions. They all started to feel invested in the mission of the software projects they joined. What was amazing is that these little contributions soon became involvement in a community, and for each of them, this community became their pathway to mastery.

As one engineer put it, "I built the GNOME Solitaire app to impress my now wife." Today, his wife helps run the GNOME Foundation, one of the most important desktop tech stacks, and now he runs Google's device accounts, user account storage, and identity data governance.

The misconception I originally had was that someone submitted a piece of code and disappeared into the ether of faceless and nameless people. But it was simply untrue. These are complex software projects filled with people who own each of the subsystems, caring for them, often with the hours of full-time employees (quite literally, they are often paid as full-time employees by companies that need them to do this work, the way that we at Endless pay people to work on the systems behind Endless OS).

These sub-communities would debate the best architecture, pontificate on the future direction of an obscure subsystem, and fight about dirty code. They became immersed in their little part of this bigger ecosystem. We outsiders come along like scuba divers thinking that these fish float around in the vast ocean, but these schools of fish live their lives around a rock in a vast reef.

Maintainers and Mentors

At the heart of every thriving open source project is a maintainer – someone who shapes the project's vision and serves as its technical gatekeeper. These individuals, whether they're the original founders or trusted successors, have the authority to accept or reject every line of contributed code. In active, high-stakes projects, maintainers take this responsibility seriously, providing detailed guidance to help contributors meet the project's standards.

Great maintainers give precise, actionable feedback – not because they're pedantic, but because they understand the true stakes of production code. Every developer knows that moment: you're three pull requests deep into what you thought was a simple feature, when a comment arrives with surgical precision:

"Please add try/catch blocks around the database operations on lines 45-52. Currently, if the DB connection fails, the entire service crashes, leaving us with no error logging or recovery path."

Your initial confidence gives way to humility as your code's weaknesses are methodically exposed by someone who's been down this road a thousand times before. The back-and-forth becomes a dance. You push changes at midnight, wake up to find another detailed review:

"The current implementation iterates through the array multiple times, leading to O(n²) complexity. Consider using a single reduce() operation to process the data in one pass. Here's an example of how we solved this in the authentication service..."

This isn't just feedback – it's mentorship in its purest form. The original 200-line change has been refined, hardened, transformed. Your pride surrendered to something better: craftsmanship.

Then one ordinary Tuesday, without fanfare, it happens. A single comment appears: "LGTM. Merging." Those simple words carry the weight of true accomplishment. Your code, now battle-tested and refined, will live in the codebase. Your name will appear in git fame, not just as someone who wrote code, but as someone who learned to write code that was good enough to make it past a guardian who really cared about quality. The next time you open a pull request, you find yourself hearing their voice in your head: "Don't forget to handle that edge case..." The lessons, hard-earned through revision after revision, become part of your coding DNA.

This is how engineering excellence propagates through the open source community – not through vague suggestions or rubber-stamp approvals, but through specific, technical direction from mentors who care deeply about the craft. Every code submission, every architectural brainstorm, every code review received and given, every scoping exercise, every heated debate, is a lesson. Like a martial artist flowing, every move brings you closer to mastery.

One day a young Cosimo grows up to become good enough to be a leader in Apple’s elite SWAT team at the heart of their operating system, and a grown Jonathan gets good enough to manage all of Twitter’s microservices and Google’s authentication layer, and a grown up Jasper goes on to build a game engine at a leading game studio, and a grown up Joaquim goes on to push the capabilities of particle accelerators at CERN. Each having become a master.

True Realm 5

And so it is in observing this that I realized this simple insight: GitHub is Realm 5.

I was recently asking the question, what is the best, most scalable school in the world. And I realized an obvious and yet surprising conclusion: if you define the "best school” as something that actually teaches you how to get a job, at scale, then the best school is GitHub.

GitHub, the primary place where engineers go to manage open source codebases, has nearly half a billion such projects. By comparison, the incredible Roblox has "only" 50 million games. This scale is staggering. These projects are teeming with 100 million engineers around the world, all contributing to these projects. Every contribution that anyone makes is them learning.

It's a living portfolio where every commit, every pull request, every code review is a lesson and proof of learning. The mentorship happens organically - senior developers review code, provide feedback, and guide newcomers through increasingly complex challenges. The curriculum is the real work itself: actual problems that need solving, real features that users are asking for.

Unlike traditional education where assignments are theoretical exercises that get discarded after grading, every piece of work on GitHub has the potential to live on and impact real users. You're not just learning for learning's sake - you're contributing to projects that power the digital world. Your "homework" might end up running on millions of devices. Your "final project" might become a crucial component that other developers build upon.

It's doing so at a staggering scale. Again, GitHub has more than 100 million active users. That's almost five times larger than the entire American higher education system. And unlike traditional education, where learning typically happens in isolated four-year bursts, GitHub represents continuous, lifelong learning. Engineers with decades of experience are still learning, still contributing, still growing their skills alongside newcomers making their first pull requests.

Open source is a little like mutations in evolution. Life as we know it wouldn't exist if DNA had been "closed-source" millions of years ago. It was the trillions of permutations that led to the magnificence that is the natural universe. Each winning mutation merged into the mainline. Nature proliferated with these permutations, the best ones stuck, and here we have humanity. It might be possible that this is also how humanity evolves to its next level - through the most scalable digital skills school ever created. These are indeed the hallowed halls of Code.

So you want to know our real insight at Endless Studios? We’ve really made one core bet: if we manage to build games like this at scale, we will be able to teach the skills of software at scale.

Some projects begin as student games, eventually built commit by commit, review by review. Others are professional games that draw students into their orbit. With each new participant, our community grows richer – more games, more opportunities for practice, more chances for mentorship, more paths to mastery.

The secret to unlocking Realm 5 may well be the same force that revolutionized software development: openness. Open our software. Open our games. Open our education. This is how we evolve – not just our code, but ourselves.