Food Mills and Ricers
A food mill is an old fashioned appliance that forces food through fine holes. It uses gentle force, provided by your elbow grease, to push the food through. So unlike a processor, any starches that are present in the food do not get gluey, and there is no additional air whipped into the mix.
Ricers are old-fashioned too, and process food in a similar, gentle manner. This tool looks like a big garlic press, or extruder. You probably had something like it in your play-dough set.
Both tools are ideal for mashed potatoes, or similar, starchy purees.