Prodigy (online service), pictures by Benj Edwards.
The service was presented using a graphical user interface. The Data Object Architecture wrapped vector and incremental point graphics, encoded as per the North American Presentation Level Protocol Syntax NAPLPS, along with interpretative programs written in the proprietary languages TBOL (Trintex Basic Object Language) and PAL (Prodigy Application Language). NAPLPS was authored in 1979 by Jerry Soloway and Bill Frezza from Bell Laboratory and Bob Bedard from CBS Laboratory.