In a food processor or blender, chop the cranberries and oranges. Don’t chop them so much that they become pureed.
Place the crushed pineapple in a mixing bowl and add the cranberries and oranges. If the relish seems watery, strain the excess juice with a fine-mesh strainer. Add the maple syrup and mix everything together.
Refrigerate for at least 2 hours before serving. Serve cold or at room temperature.