Vanilla OS
Vanilla OS, a fixed-release distribution based on Debian (formerly Ubuntu, prior to version 2) with the GNOME desktop, is an immutable operating system. The core parts of the system are locked down to prevent unwanted changes and corruption from third-party applications or a faulty update.
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GNOME OS
GNOME OS is an experimental, immutable Linux distribution that ships the latest in-development GNOME desktop, core applications and stack. It serves as a reference for developers and testers.