They’re far from perfect, I’d be the first person to tell you.
But they’re still light-years ahead of anyone else, because they’re perfectly happy just making tons of money instead of trying to squeeze every last cent out of the storefront at our expense.
Journeys (the shoe chain) and Hollister Co. both use Linux distros on their point of sale machines. Hollister’s machines are pretty locked down and can basically only run the RPoS software, but a lot of Journeys’ software is browser-based, so they have to be a bit more capable.
Pretty sure they’re both custom distros, though.