Open XML Paper Specification (also referred to as OpenXPS) is an open specification for a page description language and a fixed-document format. Microsoft developed it as the XML Paper Specification (XPS). It is an XML-based (more precisely XAML-based) specification, based on a new print path (print processing data representation and data flow) and a color-managed vector-based document format that supports device independence and resolution independence.
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.