The source documents for the online help are XML files. The XML files are written in the DocBook XML Version 4.1.2 document type definition (DTD). The DocBook XML files are converted to HTML, using stylesheets installed with the gnome-doc-utils utility and the HTML is displayed in the help browser. For more information about DocBook XML, see http://www.oasis-open.org/docbook/xml/.
The help system uses Open Source Metadata Framework (OMF) files, and a cataloging system.