Due to the type of work I do, I have often the need for small (Actually very tiny) VMs that have a functional OS to test certain basic functionality such as connectivity and quick features of automation solutions. While I could use a full blown OS for it, I have always found Tiny Core Linux to be my favorite for this use case for the following reasons:

1- It’s Open Source and free!!! Oh, yeah I would have not paid for other type of OS usually for lab or test use and used a try out version or so on, but it get tiring after a while to see your try out version expired and having to re-setup a new one at the time you most needed it, when running a demo!!