Docker is the most major example I can think of of something that only runs on Linux.

And Mac

Not natively. Docker for Mac is a thing, yes, but it’s just a wrapper around a Linux VM.

Ultimately, you can run Docker on a VM for local development, and of course you'll run it on a Linux server on production. But you don't need Canonical gatekeeping for that...

You can, but it's annoying enough that I switched to Linux at work, even though I prefer macOS as a user.

Interesting. I'm a fulltime Linux user, but wanted to try a macbook for my current job so they gave me one. I still haven't done any serious work with docker, but people tell me it runs like molasses on mac. Is that your experience? If so, I might want to switch back to Linux.

My main annoyances are:

* It is slower (might not matter depending on your workload).

* It requires manual tuning to set the correct RAM limit (whereas Docker containers on Linux are just normal processes so they just use however much RAM they need like any other process).

* It's difficult to use the normal administration tools you're familiar with: you can't, from the host, see containers running in top, or attach a debugger to them. You have to either open a shell in the container and install all the typical GNU/Linux tools there, or have some weird remote debugging setup.