No. LeivOS is its own operating system.
People who follow software ask first whether LeivOS is a Linux distribution. It isn't. There is no Linux underneath, no Unix kernel, no GNU user-space.
Then what is it?
LeivOS runs on a kernel called Uusi, written from scratch in Assembly, C, and our own in-tree language, Tape. It is not a fork of Linux, not a fork of BSD, not derived from any existing open-source operating system. The window manager, the network stack, the cryptography library, the drivers — all original work.
The end-user product is LeivOS. The kernel is Uusi. (Both names are Finnish: uusi means new; leivos is a small pastry.)
Why not just use Linux?
Linux is a remarkable project. We use it ourselves daily. We chose to write our own for three reasons:
- We wanted to remove things, not add them. Linux is enormous because it has to support everyone. We are happy supporting fewer machines if it means a system you can read end to end.
- We wanted one product, not a thousand distributions. When you buy LeivOS, you get LeivOS. There is no debate about which desktop environment, which init system, which package manager.
- We wanted a clear answer when something breaks. A bug in LeivOS is our bug. There is one place to fix it.
Will my Linux apps run?
No. LeivOS does not run Linux binaries. The system call interface is different. There is no
glibc. There is no /proc in the Linux sense.
Applications written for LeivOS use the LeivOS APIs. The system ships with a browser, mail client, file manager, notes, photo viewer, media player, and settings — see Features for the full list.
Will my Windows or Mac apps run?
No. LeivOS is not a Windows or macOS clone, and there is no compatibility layer.
How LeivOS compares.
| LeivOS | Windows | macOS | Linux | |
|---|---|---|---|---|
| How is it built? | Original kernel and user-space written from scratch. | Microsoft's NT kernel + Windows shell. | Apple's XNU kernel + macOS shell. | Linux kernel + a chosen distribution's user-space. |
| Telemetry by default | None. | Yes, multiple layers. | Yes, opt-out at install. | Distribution-dependent. |
| Ads in the system | Never. | Yes, in start menu and lock screen. | Mostly no. | No. |
| Pricing model | One-time purchase from €199. | Bundled with PC, or paid. | Bundled with Mac hardware. | Free; many distributions. |
| Account required | No. | Microsoft account effectively required. | Apple ID strongly pushed. | No. |
| Forced updates | You decide. | Yes, with limited deferral. | Background nudges. | Distribution-dependent. |
| Hardware support | Curated reference list. | Very wide. | Apple hardware only. | Very wide. |
| Source posture | OS closed (security). Tape sources available. | Closed. | Mixed (XNU open, shell closed). | Open. |
| POSIX / Linux app compatibility | No (different kernel ABI). | Via WSL / Cygwin. | Largely yes (Unix-based). | Yes. |
Comparison reflects the default behavior of stock installations as of 2026. Distributions of Linux vary widely; some match LeivOS on telemetry and updates, others do not.
Who LeivOS is for
People who want their laptop to do laptop things — browse, write, watch, work — without the rest of what a modern operating system has come to include. If that is you, read the hardware requirements next, then come back to Pricing.
Who LeivOS is not for
Gamers, professional video editors, people who depend on a specific Windows-only or Mac-only application, system administrators who need broad server-side compatibility. We are not chasing you yet, and we will not pretend otherwise.