Linux

Think of the OS as a sum of hundreds of components. You have a kernel, a boot manager, a boot and service manager system, a shell, some command line utils, drivers, a display server, a graphical interface, a sound server etc.

On a classical OS, all these components are distributed individually as packages. Which means that there is a risk of failure at any update: discrepancies on dependencies or compiler versions, failed updates, power outages etc.

"Immutable", also called "atomic" or "transactional" OSs, distribute the whole stack as a single image. If it reminds you of Docker, that's because it's exactly the same thing. An update can't fail. It's either fully applied or not at all. And that's because it's not an update at all, it's a complete system image deployed alongside the one currently in use. If it doesn't work, you can simply "downgrade" by selecting the previous image.

As simply as possible, it (mostly) locks down system files and confines users to the user directory. This makes the operating system very stable and hard to break, it also creates a reproducible testing environment which significantly helps developers with bug testing software. For the vast majority of users, this is a positive, though users that want to tinker with the system files a lot may run into a lot of blockers. Upgrades are likely to be very stable, and you will not have system file config drift issues that often break long running traditional linux distros and force the user to intervene.

It just means system libraries pinned to versions which are version controlled

It’s like a package.json or maven.xml or build.gradle or whatever but for the entire OS (An OS is really just an app that runs other apps so it makes sense to treat the deps via a dep management strat)

And if u want to swap libraries you have to layer them on using a command which will add the new library onto a commit tree, so if something breaks u just roll back

The idea is that ur pinned system libraries can get overridden and swapped out, but never have their underlying code changed or removed, so if something breaks u can just rollback to last happy version automatically at startup

Everything stays open sourced tho, it just forces stability in the system code by making sure all changes to it are versioned and tracked

You should apply for a marketing position in broadcom. The people responsible for the vmware software suite just love to do stunts like this.