Massadam (Leerdam) is the formal name, but they call it the MO special. This cheese did not start getting produced until 1980! Its popularity is due to the fact that it combines the best characteristics of gouda and swiss.
Pairing suggestions:
Wines: IPA, Stouts, Red
Meats: Cured meats, bratwurst
Charcuterie: brown mustards, sauerkraut