This is a format created in the Acorn Draw program, intended for image visualization by using vector lines. It’s used for storing information in the publishing business (brochures, logotypes, etc.). The main advantage is it’s high quality source images when printing. It’s been in use since 1980.
is an e-book format developed for the Psion Series 3 platform used in the 1990s. It contains text and its formatting parameters. This e-book format was used exclusively in Psion devices.