NixOS vs Ubuntu
Ubuntu and NixOS differ in how a system is defined, not in what it can run. Ubuntu 26.10 installs GNOME 51 and kernel 7.3 with 6 GB of memory required; NixOS generates its system from a configuration, keeps the root immutable, and boots KDE Plasma on kernel 6.12.59.
Side by side
| NixOS | Ubuntu | |
|---|---|---|
| Family | independent | deb |
| Release model | Versioned releases | Versioned releases |
| Desktop | KDE Plasma | GNOME |
| Package manager | Nix (nix-env / nix-shell) | APT (dpkg) |
| Init system | systemd | systemd |
| Immutable root | Yes | No |
| Wayland by default | Yes | Yes |
| Minimum RAM | — | 6 GB |
| ISO size | — | 6.2 GB |
| Latest kernel | — | 7.3 |
| Releases archived | 25 | 56 |
| Latest release | 30 May 2026 | 15 October 2026 |
What differs
Base & packages
Ubuntu uses APT with DEB packages and Snap channels for Firefox and Thunderbird, recording GCC 16.2, glibc 2.44 and LibreOffice 26.8.1 in 26.10. NixOS packages with Nix into the Nix store as NAR archives, recording glibc 2.40, GNOME 49, GIMP 3.0.4, Firefox 145.0.2 and VLC 3.0.21 in 25.11.
Desktop & display
Ubuntu ships GNOME 51 on Wayland only, having removed the X11 session. NixOS records KDE Plasma as its desktop with Wayland as the default, and offers a GNOME 49 graphical ISO option alongside it.
Release model
Ubuntu's releases are frequent and dated: 25.10 on 9 October 2025, 26.04.1 on 20 July 2026 and 26.10 on 15 October 2026. NixOS names releases by year and month: 25.05 on 23 May 2025, 25.11 on 30 November 2025 and 26.05 on 30 May 2026.
Hardware requirements
Ubuntu states 6 GB of memory and a 6,309 MB image. NixOS records neither a memory minimum nor an ISO size, so no comparison is possible and none is offered.
Init & immutability
systemd on both — 261 on Ubuntu 26.10, 258.2 on NixOS 25.11 — but only NixOS is immutable. That single field changes the maintenance model: Ubuntu is edited in place, while NixOS is rebuilt from configuration.
Verdict
Choose Ubuntu if you want a fixed release with GNOME 51, a stated 6 GB floor, and the largest set of third-party instructions and packages. Choose NixOS if you want the system described in versioned text, rebuilt rather than patched, with KDE Plasma and a different update model. Ubuntu asks you to maintain a machine; NixOS asks you to maintain a configuration.
FAQ
Which one is immutable?
NixOS: the immutable field is true, and packages live in the Nix store as NAR archives. Ubuntu records false.
Can both install GNOME?
Yes. Ubuntu ships GNOME 51 by default; NixOS records KDE Plasma as its desktop and a GNOME 49 graphical ISO among its options.