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.
This is an expansion of the PostScript programming language that’s often used in the publishing business. It was developed in 1982 by Adobe Systems. Before the introduction of PS, printing text and images on one page wasn’t possible. PostScript makes this possible by giving a printer commands to print out text and graphical information as needed. PS also contains print coordinates for objects on a page.