Over the first 23 years of this century, the Linux operating system has become as ubiquitous as Windows. Although only 3% of people use it on their laptops and PCs, Linux dominates the Internet of Things, and is also the most popular server OS. You almost certainly have at least one Linux device at home — your Wi-Fi router. But it’s highly likely there are actually many more: Linux is often used in smart doorbells, security cameras, baby monitors, network-attached storage (NAS), TVs, and so on.