There is a version of the internet that runs on Windows Server. It exists. But it's not the version that handles the traffic that matters.
When you load Gmail, open Instagram, stream something on Netflix, or hit an API from a mobile app, the response almost certainly came from a Linux server. Not probably. Almost certainly.
That didn't happen by accident. Linux earned that position.
The numbers first
96.3% of the top one million web servers in the world run Linux. Every single one of the world's 500 most powerful supercomputers runs Linux. Linux powers 90% of public cloud infrastructure. Of all cloud workloads globally, 49.2% run on Linux as of mid-2025. 96% of production Kubernetes clusters run Linux as their node OS.
Android, the mobile operating system on roughly two thirds of smartphones worldwide, is built on the Linux kernel.
This is not a preference. This is a monopoly built through technical merit over thirty years.
Why Linux won the server
It's free
Not free like a trial. Free as in you can download it, run it on a thousand servers, modify it, and distribute your changes. The license (GPL) ensures that remains true.
For any company building infrastructure at scale, this matters enormously. Microsoft Windows Server has a per-core licensing model. At scale, that cost compounds fast. Linux has no licensing cost at all.
It's stable
Linux servers routinely run for years without a reboot. Not weeks. Years. This matters for uptime-critical workloads where planned downtime is expensive.
The release cycle is also predictable. Ubuntu LTS releases get five years of security support. Debian's stable branch moves slowly by design. When you're running production infrastructure, slow and predictable beats fast and unpredictable every time.
It's configurable
You can strip Linux down to almost nothing. The Alpine Linux base image used in most Docker containers is under 5MB. You can run a complete Linux server with a web server, database, and application without installing a single GUI component.
On Windows, even Server Core carries overhead you didn't ask for. Linux gives you exactly what you install, nothing more.
It's secure by design
Linux uses a Unix permission model where every file and process has an owner, a group, and explicit permissions. Nothing runs as root unless it has to. The attack surface of a minimal Linux server is tiny.
The fact that the source code is public also means security researchers worldwide can audit it. Vulnerabilities get found and patched publicly, often faster than they would in closed-source systems.
The community is unmatched
The Linux kernel has over 25,000 active contributors. When a CVE drops, patches appear in hours. Documentation exists for every edge case. If your server has a problem, someone has already had it and written about it.
Where Linux lives on the internet
Web servers
Nginx and Apache, the two dominant web server applications globally, are Linux-native. Most WordPress hosting, shared hosting, VPS hosting, and cloud hosting uses one of them on Linux. The LAMP stack (Linux, Apache, MySQL, PHP) is still running millions of production websites right now.
Cloud platforms
AWS, Google Cloud, and Microsoft Azure all run Linux as the foundation of their infrastructure. When you spin up an EC2 instance, a GCE VM, or an Azure VM, you are almost always picking a Linux image. AWS EC2 instances default to Amazon Linux, which is a Linux distro. Even Microsoft, which spent years fighting Linux, now runs more Linux workloads on Azure than Windows workloads.
Containers
Docker is built on Linux kernel features, specifically namespaces and cgroups. Every container you run uses these primitives. Kubernetes, which orchestrates those containers, runs on Linux. 96% of Kubernetes clusters use Linux as their node OS.
Supercomputers
All 500 of the world's fastest supercomputers run Linux. This has been true since November 2017 without a single exception. The systems doing climate modelling, nuclear simulations, drug discovery, and AI training all run Linux.
AI infrastructure
The GPU clusters training large language models, including the infrastructure behind ChatGPT, Gemini, and Claude, run on Linux. NVIDIA's AI platforms, the tooling for CUDA, all Linux-native.
The South African angle
South Africa's internet infrastructure runs on Linux the same way the global internet does. The data centres at Teraco Johannesburg and Teraco Cape Town, which host most of the country's critical internet infrastructure, run Linux servers. MTN, Vodacom, Liquid Intelligent Technologies, and every significant South African cloud provider sits on Linux.
Local hosting providers like Xneelo, HostAfrica, Axxess, EliteHost, and Domains.co.za all run Linux on their server infrastructure.
If you're building a product that runs online in South Africa, it's running on Linux. Understanding that infrastructure is not optional for anyone who wants to call themselves a senior engineer.
What this means for you as a developer
You don't need to be a Linux sysadmin to build software. But you should know:
- How to navigate a Linux filesystem from the command line
- How to read system logs (usually in
/var/log/) - How to check what's eating CPU and RAM (
htop,top) - How to manage background processes with
systemdorpm2 - How file permissions work (
chmod,chown) - How to use SSH and basic
scporrsyncfor file transfers
These skills don't take long to learn and they will save you in production situations that matter.
Linux won the internet because it was technically better for the job. Learning to work with it isn't niche knowledge. It's the floor.