Ubuntu or linux both free i think see the teckie thread their talking about it 😄

There are alternatives depending on what you want to do, what you use it on, and what you are prepared to accept.

Some of those Include   linux , android, Chrome, macOS,  etc, but one of the problems is that of usability. If someone, or site or  doesn't think it's worthwhile supporting your OS, it can be a problem. Buy a new bit of hardware only to find out the manufacturer doesn't provide drivers for your OS and it can be frustrating.