Link: https://itsfoss.com/open-source-non-linux-os/

Every system listed below is open source and not powered by Linux. Each has an ISO or installer you can boot today, and many of the picks can even run Linux applications.

Think of it as a list of operating systems that are friends with Tux but not friendly enough to call him inside for a cup of tea.

This list is not ranked.

Vinix

If you own an Apple Silicon MacBook and want a system that is neither macOS nor a Linux distribution, Vinix is aimed at you. Only the original M1 is supported today, and Alexander Medvednikov, the author of V, maintains the project.

The kernel is monolithic and written mostly in V, while part of it is C and assembly. Because memory is managed by hand, no garbage collector can interrupt a system call, and the security model borrows certain concepts from OpenBSD.

On ARM64, it runs Alpine Linux binaries natively, and pkg installs packages from Alpine's aarch64 repositories. ISOs for both x86-64 and ARM64 are available for virtual machine use.

A good pick if you enjoy poking at experimental kernels.

Asterina NixOS

Trying Asterinas NixOS means setting up a NixOS system and finding a Rust kernel where Linux should be. Asterinas is that kernel, and because it implements Linux's system call interface, apps for the Linux platform run on it.

The distribution is configured through Nix like regular NixOS, and unsafe Rust is allowed only inside a small framework called OSTD, while the rest of the kernel, along with its drivers, is safe Rust.

x86_64 is the fully supported platform, and ARM64 and RISC-V sit one tier below it. The project says the distro is not ready for production use and aims the installer ISO on GitHub at early adopters and enthusiasts.

A good pick if you follow the implementation of Rust in operating systems.

Redox OS

Where Asterinas swaps Rust in under NixOS, Redox OS builds the whole system from scratch in Rust. It’s a Unix-like OS with a microkernel design, and Jeremy Soller of System76 created and maintains it.

You get the Orbital desktop, a pkg package manager, and several apps from System76’s COSMIC desktop. Linux and BSD software has gotten much easier to port too, and the project has recently been focusing on making Redox boot reliably on real hardware, not just in a virtual machine.

A good pick if you want to see how far a pure Rust operating system has come

FreeBSD

FreeBSD is a complete operating system derived from BSD, the Unix version developed at the University of California, Berkeley. A large community maintains it, and its license lets companies keep their own changes private.

ZFS, jails, and a hypervisor sit at the center of what it offers. OpenZFS is built into the base system, and boot environments let you roll back a bad update by snapshotting the system first.

Its recent release, FreeBSD 15.1, came out earlier this year, and the OS runs on hardware platforms like AMD64, AArch64, Armv7, PowerPC, and RISC-V.

A good pick if you run servers, storage, or networking gear.

GhostBSD

GhostBSD is FreeBSD with the desktop work already done. The project pairs a FreeBSD base with the MATE desktop and offers a set of applications that make users feel familiar with using it.

The name started as shorthand for GNOME hosted by FreeBSD. MATE, the desktop it ships today, is a continuation of GNOME 2, and the old name still fits.

Updates arrive on a slow-rolling schedule, and the project says it values a stable cycle over chasing the newest software the way some Linux distros do. The current release, 26.1-R15.0p2, came out in April on a FreeBSD 15.0 base.

Also good to know is that Linux binary compatibility comes preconfigured, and an installer built on OpenZFS keeps setup approachable for newcomers.

A good pick if you want FreeBSD as an everyday desktop.

Haiku

Haiku is an open source operating system inspired by BeOS that is aimed at personal computing. The same team writes the kernel and the desktop applications, with the project crediting that approach for the system's consistent interface.

Under that interface sits a kernel built for responsiveness, a system that is multithreaded throughout, and a BFS file system whose indexed metadata lets Tracker, the file manager, run database-style queries across a drive.

Software installs are handled via packages that mount into the system, and earlier states are kept for rolling back botched updates.

A good pick if you are looking for a uniform desktop experience.

ReactOS

ReactOS comes with a warning label attached because the OS is still considered alpha-level software, and the download page promises nothing about stability, the safety of your files, or whether it would work on your hardware.

Behind the warning is a full operating system with a Windows-style desktop that the project says was written from scratch, while most of its user-mode code is based on Wine, the ubiquitous compatibility layer.

By default, it installs only onto a FAT16 or FAT32 partition, and Btrfs support is experimental.

A good pick if you want to see how far an open source Windows reimplementation can go.

FreeDOS

If you have old DOS games, legacy business software, or a BIOS flashing tool that won’t run anywhere else, FreeDOS is the one to grab. It’s a complete MS-DOS compatible operating system, started by Jim Hall in 1994 and still maintained today.

It runs on everything from an original 8086 to a modern PC, though newer machines need legacy BIOS mode or UEFI with legacy boot turned on. The requirements are tiny too: 640 KB of RAM and about 20 MB of disk space for a basic install.

You get a Live CD, a USB installer for real hardware, a Legacy CD, and even a floppy edition. I’d start with the Live CD in a virtual machine, which is also what the project recommends for most people.

A good pick if you want to run DOS games and legacy software on real hardware.

KolibriOS

KolibriOS is an operating system small enough to fit on a floppy disk. Which sounds weird because no modern computer comes with floppy disk anymore. Even CD drive are rare these days.

But then, the KolibriOS is not meant for modern computers anyway. You need just an i586 processor, 12 MB of RAM, and a few megabytes of disk space. It doesn’t follow POSIX either, so don’t expect to port your Unix tools over.

The kernel and drivers are written entirely in FASM assembly, which is why it boots to a GUI in seconds and opens apps almost instantly.

Despite its tiny size, you get a text editor, an image viewer, a graphics editor, a web browser, and over 30 games. It fully supports FAT12/16/32 and can read NTFS, exFAT, and ext2/3/4 partitions.

The project is still very active, so worth considering it in your retro tool kit.

A good pick if you are into retro computing or if you want to keep the 90s computer alive.

A suggestion

Try these operating systems in a virtual machine before switching. I say that because it’s a good habit to test out such non-standard pieces of kit before committing to them on your hardware.

First see what works for you. Then see if your workflow and usage habits align with what the OS offers. Once you settle on one, keep it updated so you never miss critical patches.

Air-gapped setups are better protected from such risks, of course.

that's it, linux has gotten too mainstream. time to look for an alternative.

The only one I can imagine getting a following is Asterina. Built on NixOS, it's probably the only one that could even bring along most of the stuff that currently runs on Linux.

Especially hardware support will be a limiting factor.

lol, it's the year of linux, finally! Aight, I'ma head out lmao

5% active users on Steam... way too many people, I'm switching to punch cards to be annoyingly persnickety about my personal technology and signal how much of tech hipster I am.

React just got experimental NTFS install support

FreeBSD is awesome, I used to install it on the servers I would setup for clients back in the day and it would handle any server hardware at the time.

TempleOS is the one and only OS

I switched to OpenBSD about a month ago and I absolutely love it. it's not my daily driver. It's smooth, incredibly easy to install and upgrade (just did it today with the release of 8.0) and has everything I need and everything works. found the wifi works a hell of a lot better, almost on par with Linux, than FreeBSD.

Also I really like Haiku. that's a fun simple OS and the fastest install I've ever experienced.

The problem is Linus Torvalds has fallen to AI.

Redox looks promising too. I’m really interested to see if a modern microkernel can be performant.

A world of pure rust instead of C does sound enticing. But it'll still suffer from hardware support. Well, unless people throw billions of tokens at it to write their drivers and actually share that with others. But I'm assuming people want to leave Linux because of AI use, so that'll also piss of the anti-AI crowd 🤷

There are barely enough kernel devs for linux, I don't know where all the kernel devs for these other OSes are going to come from.

TempleOS

o==]==========>

The only OS sanctioned by the Pope.

I wonder how many people saw this coming.

I get the sense that a lot of people were blindsided recently, not only from large recent donations to some groups, and Linus using AI... but also OSI declaring a focus on politics.

Iirc redox can run linux under a hypervisor to use its drivers

From when I tried Kolibri on VM, a fair chunk of the software wasn't there yet and didn't really work. So I wish them the best of luck and hope it can become at minimum hobbyist machine levels of working and success in the future.

Would like to hear more about your Haiku experience. Is it a decent daily driver?

edit: https://www.haiku-os.org/about/faq

Can I use Haiku as my primary Operating System?

Yes! Although the OS is still considered “beta”, it is reasonably stable and can be used to perform most daily tasks such as browsing the web writing and reading e-mails, or listening to music and watching videos. We strongly recommend that you make backups of your personal files regularly.

Can Haiku connect to the Internet?

Yes! We reuse network drivers from FreeBSD, so most network adapters will work on Haiku out of the box. Haiku includes an e-mail client and a web browser, and you can install other network-enabled applications.

My motive for liking this article is that I initially moved off of Windows onto Linux due to the Recall drama and AI getting shoved in. And now a lot of AI-generated code is going into the Linux kernel. So I was wondering if there were any viable alternatives. I'm not looking for alternatives for clout or to show how much of a genius I am compared to all those normies. I'd actually prefer if there was a popular alternative that matched my requirements, especially since because I'm not a genius. More users = more people asking and answering different support questions = it's easier for me to self-solve any problem that occurs without investing all the hours needed to become an expert.

(If none of them have enough documentation or compatible needed applications for my non-expert self, I was going to go with Gentoo, and if I still cannot figure that out, any Linux distribution is still probably better than Windows or Apple on 1) preloading generative artificial intelligence features onto the OS and making them hard to take out and 2) not training AI on your data.)

Also, it is nice to find out about people making other options. Right now I was mostly under the impression there were three options: Windows, MacOS, and the many Linux distributions. I figured there were a few niche OSes out there. This article makes them more "real" to me. In a society where our choices are increasingly being narrowed to a few brands, and alternatives to the big guys keep getting acquired, I like to see different options existing, that people invested their time and love into these cool projects. (Yes, I do understand that Windows and MacOS are the big guys and Linux is much smaller from a non-server-admin viewpoint.)

I'm sure there are other genuine motives for liking the article as well, as opposed to clout-chasing ones.

it can be. if you're looking for something for browsing, watching video/listening to music, wee bit of coding/writing it works well. it has a few applications that the BSDs don't. I like the floorp web browser and none of the BSDs have that packaged, Haiku does.

it's VERY easy to install, VERY quick to install.