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.
was developed for the first mass-produced e-book reader – Rocket eBook. The format is written in Ruby. RB files are containers holding the entire content for a Rocket eBook device. It has DRM protection capability which is not used in the books published at present due to the format’s lack of popularity.