The world's operating systems on Technical Notes

Introduction and method - 1/6

Mon, 01 Jan 0001 00:00:00 +0000

What this is about#

Ask “which operating system dominates the market?” and the conversation almost always slides toward a single arena: Windows versus macOS on the desktop. That is a narrow view. The software that really runs the world mostly executes elsewhere — in the billions of connected devices (internet boxes, televisions, cars, surveillance cameras, industrial sensors…), in the billions of phones, in the servers that answer every web page, in game consoles, cash machines, and all the way up to supercomputers.

Where Windows retreated or never broke through - 2/6

Mon, 01 Jan 0001 00:00:00 +0000

Let’s start with the segments where Windows eventually vanished. They cover two distinct realities. In some cases, Windows held a real position before being supplanted: the smartphone (Windows Mobile peaked at ~42% of the US smartphone market in 2007), the enterprise firewall, automotive infotainment. In others, it is a failed foray — Microsoft tried to enter without ever taking root: the tablet, the smartwatch, the virtual-reality headset, network storage. In both cases the dates are precise, because a software retirement can be dated — to an end of sales, to an end of support.

Where Windows never reigned - 3/6

Mon, 01 Jan 0001 00:00:00 +0000

Second category: the segments where Windows was never the dominant system — there was no Windows to replace. These markets were already held by Unix (often proprietary: Solaris, AIX, HP-UX, IRIX), and it is Linux and BSD that took over from Unix. On this ground, the real loser is not Windows: it is yesterday’s proprietary Unix.

The strongholds Windows still holds - 4/6

Mon, 01 Jan 0001 00:00:00 +0000

Third category: the segments where Windows is still dominant. They share a common trait, which we will come back to — most of them are old conquests, won twenty to thirty years ago against Unix, OS/2 or Novell.

The breaches: where Windows is receding - 5/6

Mon, 01 Jan 0001 00:00:00 +0000

The three segments gathered in this article share one thing: Windows was genuinely present there, often dominant, but its position is receding. So these are neither lands where Windows never reigned, nor strongholds it holds firmly — they are breaches. The most emblematic is its last great stronghold, the desktop; then come two older conquests in reflux, databases and game consoles.

How many systems in the world, and conclusion - 6/6

Mon, 01 Jan 0001 00:00:00 +0000

One last exercise, openly speculative but illuminating. One cannot census every system deployed on Earth; one can, however, set orders of magnitude, clearly separating the sourced from the assumed.

Four sourced anchors (primary figures):

Population	Number	Kernel family	Source
Active Android devices	> 3 billion	Linux	Google, 2025
Active Apple devices	~2.5 billion	BSD/Darwin	Apple, 2026
Active Windows devices	~1.6 billion	NT	Microsoft, 2026
Connected objects (IoT)	~21 billion	Linux / RTOS	IoT Analytics, 2025

To this we add estimates, for lack of recent public figures. Servers, first: the fleet numbers in the tens of millions of physical machines (worldwide shipments run at around 12 to 13 million a year), and far more virtual instances; system-side, Linux is largely dominant there — a 2017 IDC report already gave, across all deployments, Linux ~68% against Windows ~32% (Windows remaining No. 1 only in the paid market). Then the detail of the desktop (Mac, ChromeOS, Linux).

The world's operating systems on Technical Notes

Introduction and method - 1/6

What this is about#

Where Windows retreated or never broke through - 2/6

Where Windows never reigned - 3/6

The strongholds Windows still holds - 4/6

The breaches: where Windows is receding - 5/6

How many systems in the world, and conclusion - 6/6

How many systems in the world, and what share for Windows?#