In a medium saucepan over medium-low heat, combine the cranberries, maple syrup, water, orange zest, and salt. Bring to a simmer, stirring often so that the maple syrup doesn't burn.
Reduce the heat to low and cook, stirring frequently, until the cranberries burst and their juices thicken, 15 to 20 minutes, keeping in mind that the sauce will continue to thicken as it cools. Taste and add more sweetener or orange zest, if desired.