For web output the Saxon XSLT processor was used to convert the docbook XML directly to HTML.
For print output the Saxon XSLT processor was used to convert the docbook XML to Formatting Objects (FO) XML.
For general print documents the FO XML is converted to PDF and Postscript with the Apache project FOP utility.
For six by nine inch book output the Render X XEP digital typography tool was used to convert the FO XML to print ready PDF output.
The cover designs were developed in the GNU Image Manipulation Program (GIMP).