A frankfurter is a smoked, seasoned sausage of beef, pork, or a blend of the two, encased and typically boiled, grilled, or steamed before serving. It takes its name from Frankfurt, Germany, where sausage-making has a long documented history, though sources disagree on exactly when the frankfurter itself first appeared. It is closely related to, and often used interchangeably with, the wiener (named for Vienna); the two sausages' overlapping history is a point of ongoing dispute among food historians rather than a settled fact. Frankfurters are the sausage most commonly used in hot dogs, served in a soft bun with mustard, ketchup, relish, or sauerkraut, and are also sliced into stews, casseroles, and bean dishes. Their flavor is savory and mildly smoky, with a firm, snappy texture from the casing.