Libostree

Since I share your frustration, from Wikipedia [0]:

> libostree (previously OSTree) is a system for versioning updates of Linux-based operating systems. It can be considered as "Git for operating system binaries". It operates in userspace, and will work on top of any Linux file system. At its core is a Git-like content-addressed object store with branches (or "refs") to track meaningful file system trees within the store. Similarly, one can check out or commit to these branches

[0] https://en.wikipedia.org/wiki/OSTree

Agreed that the page is incomprehensible unless you already know what OSTree is.

You could see as Git for operating system binaries. You can pull new versions and the currently booted system is a checkout.

It provides many benefits, like atomic updates/rollbacks, integrity checking, signed commits, etc.

Some distributions use OSTree, like Fedora Silverblue and CoreOS. Flatpak also uses OSTree as its store.

OSTree solves a pretty narrow problem of downloading an app or OS update and unpacking it on disk in an efficient way (forest of hardlinks). Then you can reboot into the new version. Last I checked, OSTree treats the OS as a single image, it doesn't help you build the image at all, and it can't compose multiple images.

Nix/Guix is a package manager that does a lot more than OSTree, such as building packages from source and composing multiple packages into a full system.

Yes! Fedora Silverblue (ostree based Linux distribution) ISO already contains images for PXE booting.

But mind you; I'm quite sure it still uses overlayfs or device mapper snapshots for the root filesystem.