The original (heavy) weight was designed by Bob Newman in the Letraset studio and issued in 1970. In 1978, Frankfurter Medium (the only style to include a lowercase, by Alan Meeks) and Frankfurter Highlight (by Nick Belshaw) were added. Frankfurter Inline (by Studio) followed in 1981. [Daines]
URW had versions named Freyja and Frigorius, including Shadow, Outline, Small Caps and Chrome variants. Latter is Frankfurter Highlight inversed, with an outline.