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.
is a format developed by the International Digital Publishing Forum. It is characterized by the XML- and XHTM-based optional use of CSS styling. The main feature of this format is the use of reflowable text (word wrap) which makes it possible to adapt the image to different device displays. The ePub file is a zip-archive with an .epub extension.