The first Zainium OS ISO

The first public ISO snapshot of Zainium OS, 2026.11.06, is out: download it here (2 GB). It boots into the complete COSMIC desktop without touching your disk, and the installer is one click away. If the screen locks in the live session, the password is where_is_usr_bin.

What is in it

• COSMIC 1.11.0, the whole desktop, built from source for Zainium OS.
• Linux 7.3.1 with sealed OverlayFS: the base is read-only even for root, and every base and boot file is sealed with fs-verity.
• quantra-ramfs 6.1, our Rust initramfs, with journaled base upgrades.
• zex 6.0, the package manager, with four sources: Zainium, Void, Alpine and Chimera.
• musl as the base C library, with glibc next to it when you need it.
• Limine 12.9 as the boot loader, updated with elevate zex kernel --u.

For the full story, read how Zainium OS works, from zero.

New since the last update

• Hardware: firmware for laptops and desktops is now a package, Intel laptop sound (SOF) and the WiFi regulatory database included. Phone and server firmware is left out, which saves more than 400 MB.
• Installing software on the sealed system: zex install, reinstall, remove and uland --u write to the user layer directly, and new software appears at once, without a reboot.
• System paths: every path in musl now points to the Zainium layout, so users, DNS and the time zone never depend on a directory at the root that does not exist.
• Your choice: sealing your installed software with fs-verity is now optional.
• Upgrades: every package stays visible with its progress bar during an upgrade.

Why the kernel is patched

Stock OverlayFS lets root remount a read-only overlay as writable, and it does not allow its upper layer to change while mounted. Zainium OS needs the opposite of both: a base that nobody can remount, and software that appears the moment it is installed. The sealed mount option adds exactly that, and it is one of only three patches on the kernel. In this release it also shows replaced and removed files at once, and a directory in use no longer fails with Stale file handle when software is installed next to it. The kernel page explains the design.

Known limits

• BIOS boot works from a USB drive; a disc boots with UEFI only for now.

Reports

• Security report
• glibc test report

Already running Zainium OS?

elevate zex update
elevate zex kernel --u

ISO snapshots are only a fresh starting point: an installed system stays current on its own.