There's a world out there beyond Windows, macOS, Android and iOS - and it's a world worth exploring. The big 4 operating systems are built to be useful to as many people as possible. Yet many of us have very particular needs and might do better with something more streamlined. Thankfully there are a lot of programmers with needs as particular as our own. Sometimes they build operating systems dedicated to certain computers and smartwatches, or ones intended just for gaming. Other times they're out tweaking and refining what's already available.