1) Pizza sauce originated in Naples, Italy in the 18th century when tomatoes were added to yeast-based flatbread by poor locals. 2) In addition to traditional tomato sauce, pesto, bechamel, salsa, barbecue, pumpkin, tapenade, carrot and harissa, pepper jelly, caramelized onion, chimichurri, Thai chili, curry, and tandoori sauces can also be used on pizza. 3) The document provides recipes for alternative pizza sauces and encourages experimenting with different sauces beyond traditional tomato.