This website is the “remains” of the Qtrac Ltd. website
(www.qtrac.eu).
Qtrac Ltd. was founded in 2006, traded until 2024, and was wound up in 2025.
The “Qtrac” in Qtrac Ltd. stood for “Quality Training Research And Consultancy”. Qtrac Ltd. began with the intention of providing programming training courses. However, in its first eight years it mostly earned money from the books written by Mark Summerfield its owner and sole employee, plus income from providing technical writing services and programming training courses. During Qtrac Ltd.'s last decade, most of its income was generated by license sales of its PDF comparison products, in particular the DiffPDF GUI application and the more technical comparepdfcmd tool (itself the successor to the diffpdfc tool). In 2023 Qtrac Ltd. stopped selling its software to European customers due to the EU's Cyber Resiliance Act. This cost Qtrac Ltd. about half its sales. Nonetheless the company continued. For almost eleven years Qtrac Ltd. sold its software using Digital River/MyCommerce (DRMC) to handle the payments. Unfortunately, from mid-2024 DRMC stopped passing on the money it received to its customers. This led directly to Qtrac Ltd.'s closure in 2025.
We also produce some free open source software, mostly small libraries and utilities, many listed in the Site Map. And many years ago we also created a free open source DiffPDF application, now long maintained by others.
All of our books are published by InformIT (Pearson Education), although they are all out of date now with no prospect of new editions.
By email Mark can be contacted as m.n.summerfield (gmail—dot com).
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