Some restaurants offer you packets of ketchup while others offer you some paper cups and a ketchup pump. But, I was just at a Micky Ds. that had ketchup on tap.
The ketchup dispenser was pressurized. All you had to do was put the paper cup under the nossle and pull the handle and you had ketchup.
I liked the ease of use but I suspect that it might be a maintenance nightmare. Regardless, dispensing ketchup was quick and easy.