List of free, open source operating systems
Updated: May 18, 2026
Please note that in some cases, such as with Qubes and Asahi Linux, they are technically "distros" of Linux. However, given their extreme departure from what normally constitutes a Linux distribution, I've listed them here. And allow me to say I have a ton of respect for said projects.
- OpenBSD
- Linux
- FreeBSD
- NetBSD
- Dragonfly BSD
- Qubes OS
- Asahi Linux
- Haiku
- Redox
- Serenity
- ReactOS
- AROS
- Supported hardware: Aros/Platforms/x86 Complete System HCL
- FreeDOS
- BASIC-DOS
- Visopsys
- Blog series: Writing an OS in Rust
- skiftOS
- RetrOS-32
- Tock
- Hubris
- Essence
- Subgraph OS
- Ares
- osv.io
- axle OS
- hk
- Snowdrop OS
- Astral
- vekos
- Essence
- Barrelfish
- ToaruOS
- MyraOS
- Mezzano
- House
- Minoca OS
- Kerla
- SOS
- PowerNex
- Interim OS
- KolibriOS
- MINIX
- RISC OS
- HelenOS
- GeckOS/A65 V2.0
- GNU Hurd
- Plan 9
- Harvey
- illumos
- AquilaOS
- NuttX
- Sculpt
- Biscuit
- Xv6