This is a condiment or jelly similar to jelled cranberry sauce in it's sweet-tart appeal, but made from quince.
It is popular in Spain and in all the lands that they colonized. I saw kosher versions (tinned) in Argentina, and I have heard that Sephardim use it.
Is a kosher version available in the US?
I do know that I could make my own, I'm just not feeling that ambitious.