Vision Matei Radu

Why Fabius Launches First on Windows

Fabius starts with Windows not because Windows is the only platform that matters, but because it is the first platform we need to secure if we want to rapidly reduce real risk for European users.

Our strategy is simple:

  1. Start with the most widely used operating system on PCs/laptops in Europe;
  2. Consolidate cross-platform components and sovereign open-source stack;
  3. Move on to Linux, distribution by distribution;
  4. Expand coverage to macOS, Chrome OS, and any other relevant systems in the European market.
Fabius is built for a broader vision: euphile.eu as a European sovereign tech infrastructure, where open source plays a central role. Windows is the first operational step, not the final destination.

The Problem: The Developer’s Work PC is a Critical Zone

Developers are not ordinary users. Their work PCs have access to code, tokens, SSH keys, private registries, CI/CD pipelines, cloud infrastructure, internal packages, and sensitive data.

This means a compromised endpoint doesn’t just affect one person. It can become an entry point into a company’s software supply chain.

For Fabius, the question isn’t just:

> “On which operating system should we start elegantly?”

But:

> “Where can we most quickly reduce the greatest risk for European users?”

Our answer, at this moment, is Windows.

Windows is the Most Used Operating System on PCs/Laptops in Europe

In the general desktop/laptop market in Europe, Windows clearly dominates.

According to StatCounter, in Europe, for the desktop category—which includes desktops and laptops—Windows held 65.68% market share in April 2026. In the same dataset, OS X had 11.29%, macOS 4.69%, Linux 3.31%, and Chrome OS 1.51%. StatCounter notes that laptops are included in the desktop category because the browser’s user-agent does not allow reliable separation from desktops. (gs.statcounter.com)

| Desktop Operating System, Europe | Market Share |
|---|---:|
| Windows | 65.68% |
| Unknown / Unidentified | 13.51% |
| OS X | 11.29% |
| macOS | 4.69% |
| Linux | 3.31% |
| Chrome OS | 1.51% |

If we aggregate OS X and macOS, the Apple desktop ecosystem reaches about 15.98%. Even so, Windows remains by far the largest surface area for PC/laptop use in Europe.

pie title Desktop/Laptop OS Market Share in Europe, April 2026
    "Windows" : 65.68
    "Unknown" : 13.51
    "OS X" : 11.29
    "macOS" : 4.69
    "Linux" : 3.31
    "Chrome OS" : 1.51

These data do not measure the exact number of installed devices, but rather web usage. StatCounter explains its methodology: the data comes from over 3 billion monthly page views, collected from over 1 million websites using StatCounter tracking. For each page view, StatCounter analyzes the browser, operating system, resolution, and device platform. (gs.statcounter.com)

Even with this methodological limitation, for the question “Where are European users on PCs/laptops?”, the data is clear enough: Windows is the first place we need to be present.

Even for Developers, Windows Remains the Top Individual OS

In the developer community, the picture is more nuanced. Linux is far more important than in the general market, and that matters greatly for Fabius. But we must distinguish between:

In the Stack Overflow Developer Survey 2025, when asked about the primary operating system used at work, Windows appears with 49.5% for professional use, macOS with 32.9%, Ubuntu with 27.7%, Linux non-WSL with 16.7%, WSL with 16.8%, Debian with 10.4%, Red Hat with 5.7%, Arch with 4.6%, Fedora with 3.7%, NixOS with 1.8%, Pop!_OS with 1.1%, and ChromeOS with 1.2%. The Stack Overflow 2025 survey had over 49,000 responses from 177 countries, and the operating systems section received 31,569 responses. (survey.stackoverflow.co)

| OS Used Professionally by Developers | Market Share |
|---|---:|
| Windows | 49.5% |
| macOS | 32.9% |
| Ubuntu | 27.7% |
| Windows Subsystem for Linux | 16.8% |
| Linux non-WSL | 16.7% |
| Debian | 10.4% |
| Red Hat | 5.7% |
| Arch | 4.6% |
| Fedora | 3.7% |
| NixOS | 1.8% |
| ChromeOS | 1.2% |
| Pop!_OS | 1.1% |

At first glance, if you add up all Linux distributions and usage modes, the Linux ecosystem becomes very large among developers. But for developing an endpoint security product, this aggregation can be misleading.

For marketing, “Linux” may be a single category. For engineering, it is not.

Ubuntu, Debian, Fedora, Arch, Red Hat, NixOS, and Pop!_OS have real differences in packaging, update models, kernel versions, system services, permissions, desktop integration, signing, distribution, and user expectations. Additionally, WSL is a separate case: it runs over Windows and has a different security and integration model than native Linux desktop.

That’s why the fact that Linux is large for developers doesn’t mean it can be treated as a single platform launched in one step.

flowchart TD
    A[Fabius rollout] --> B[Windows]
    B --> C[Linux: Most popular distribution]
    C --> D[Other Linux distributions]
    D --> E[macOS]
    E --> F[Chrome OS]
    F --> G[Other relevant platforms in Europe]
    B --> H[Rapid protection on Europe’s largest surface]
    C --> I[Consolidation of open-source and EU sovereign tech]
    D --> I

Why We Don’t Launch Everything Simultaneously

A security application is not an ordinary application. It must be stable, predictable, and correct in edge cases. If a security product fails, it can block the developer, create false positives, miss dangerous behaviors, or introduce friction into a critical workflow.

That’s why we choose a controlled rollout.

A significant part of Fabius is or will be cross-platform. However, the final application must respect the details of each operating system: permissions, background services, update mechanisms, shell integration, file access, processes, networking, and environment-specific behaviors.

To maintain control over quality, we prefer to deliver well, one by one, rather than promise superficial support for all systems at once.

flowchart LR
    A[Cross-platform core] --> B[Windows app]
    A --> C[Linux app]
    A --> D[macOS app]
    A --> E[Chrome OS support]
    B --> F[Deep testing]
    C --> F
    D --> F
    E --> F
    F --> G[Quality, consistency, trust]

Linux Follows and Remains Strategic

Windows is the first step because it is the most urgent from a coverage perspective. But Linux remains strategic to our vision.

If we want European sovereign tech, we cannot ignore Linux and open source. On the contrary: Linux is one of the natural foundations for a more transparent, auditable, and independent European stack.

For us, Linux is not a secondary platform. It is an essential part of Fabius’s direction and euphile.eu.

Our plan is to start with the most popular Linux distribution relevant to our developers, then gradually expand support to other distributions. Ubuntu is a natural candidate for the first Linux step, being the most used Linux distribution reported in the Stack Overflow Developer Survey 2025: 27.7% professional use, ahead of Debian, Red Hat, Arch, Fedora, NixOS, and Pop!_OS. (survey.stackoverflow.co)

What This Means for the Roadmap

Our roadmap can be summarized as follows:

timeline
title Conceptual Fabius Roadmap
    Windows : First rollout
            : Largest desktop/laptop surface in Europe
            : Priority for reducing supply chain attack risk
    Linux : Next step
          : Start with the most popular distribution
          : Expand distribution by distribution
    Premium security : Consolidation toward full antivirus
                     : More automation
                     : More endpoint coverage
    Cross-platform : macOS
                   : Chrome OS
                   : Other relevant platforms in Europe

In the short term, we start with Windows for impact. In the medium term, we accelerate on Linux for the open-source vision and European technological sovereignty. In the long term, Fabius must become a complete security product, covering all relevant systems for the European market.

Most likely, once we cover the premium area and approach full antivirus capabilities, the pace of expansion across distributions and platforms will increase. The reason is simple: once the product’s core is mature, each new platform becomes easier to support without sacrificing consistency.

The Short Answer

Fabius launches first on Windows because Windows is the largest risk surface on PCs/laptops in Europe and remains the most used individual system in the professional environment of developers.

But Windows is not the end of the strategy. It is the first step.

Linux follows because it is essential for developers, for open source, and for our vision of European sovereign tech. macOS and Chrome OS will also be covered. And the final goal is clear: Fabius must protect all relevant systems for the European market without compromising quality, consistency, or trust.

Sources