| MotoMagx | Motorola | — | — |
| MoviX | — | — | GNU General Public License |
| Mubuntu | — | — | — |
| Musix GNU/Linux | — | — | — |
| MX Linux | — | — | GNU General Public License |
| MyLinux | — | — | — |
| Mythbuntu | — | — | GNU General Public License |
| MythDora | — | — | — |
| Navigatrix | — | — | GNU General Public License |
| NepaLinux | Madan Puraskar Pustakalaya | — | GNU General Public License |
| NetHunter | — | — | — |
| Netrunner | Blue Systems | — | GNU General Public License |
| NetSecL OS | — | — | GNU General Public License |
| Newtoos | — | — | — |
| NimbleX | — | — | — |
| Nitrux | Camilo Higuita | — | — |
| NixOS | Thomas Tuegel, Eelco Dolstra | — | MIT License |
| NND | — | — | — |
| Nobara (operating system) | Thomas Crider | — | — |
| NodeOS | — | — | MIT License |
| NOI Linux | — | — | — |
| Nonux | — | — | GNU General Public License |
| Nova | University of Information Science | 2014 | GNU General Public License |
| NUbuntu | — | — | — |
| Nura | — | — | GNU General Public License, version 3.0 |
| NuTyX | — | — | GNU General Public License |
| NVIDIA DGX OS | Nvidia | — | — |
| Nyarch | — | — | — |
| Ojuba Linux | — | — | GNU General Public License |
| Omarchy | David Heinemeier Hansson | — | MIT License |
| Open School Server | — | — | — |
| OpenCGX | MontaVista | — | — |
| OpenDingux | — | — | — |
| OpenELEC | — | 2009 | GNU General Public License |
| OpenEuler | — | — | — |
| OpenHD | — | — | GNU General Public License |
| OpenIPC | Igor Zalatov | — | MIT License |
| Openmamba | — | — | — |
| OpenMandriva | — | — | GNU General Public License |
| OpenMediaVault | Volker Theile | 2009 | GNU General Public License, version 3.0 |
| Openmoko Linux | Openmoko | — | GNU General Public License |
| OpenSUSE | OpenSUSE Project | — | GNU General Public License |
| Openwall Project | Alexander Peslyak | — | — |
| OpenWrt | Gábor Juhos, Florian Fainelli, Hauke Mehrtens, Jo-Philipp Wich | 2004 | GNU General Public License, version 2.0 |
| OpenZaurus | — | — | GNU General Public License |
| Oracle Linux | Oracle Corporation | 2006 | GNU General Public License |
| Oralux | — | — | — |
| OS/VX | — | — | GNU General Public License |