Linux is a tried-and-true, open-source operating system released in 1991 for computers, but its use has expanded to underpin systems for cars, phones, web servers and, more recently, networking gear.
Listening to music on a Soundcore speaker or headphones? Check out the number 3.
The anonymizing Linux distribution for USB sticks, Tails, has been released in version 7.4. It fixes minor bugs.