Binary package “fop-doc” in ubuntu bionic

XML formatter driven by XSL Formatting Objects (doc) - doc

 FOP is a Java application that reads a formatting object tree and then
 turns it into a wide variety of output presentations (including AFP,
 PCL, PDF, PNG, PostScript, RTF, TIFF, and plain text), or displays
 the result on-screen.
 .
 The formatting object tree can be in the form of an XML document
 (output by an XSLT engine like xalan) or can be passed in memory as a
 DOM Document or (in the case of xalan) SAX events.
 .
 This package contains the documentation.