Here’s a few that I know of. What other things are commonly running Linux that most people may but be aware of?
- Ingenuity (helicopter drone on Mars)
 - Smart TVs and streaming devices (Samsung’s TizenOS and Roku devices)
 - Smart appliances (Samsung’s smart refrigerator)
 - Digital signs and billboards
 - My car stereo (Sony XAV-AX6000)
 - The Large Hadron Collider
 - FAA Air traffic control and radar systems
 - Self driving cars
 


Kindles too. You can jailbreak them and get a shell. They’re so much more useful when they’re jailbroken. They can read multiple other formats, they can get books from a fileserver on your local network, the jailbroken reader app is better, etc.