Qtrac Ltd was founded in 2006. Initially it provided consultancy (software development, technical writing and editing), as well as training for programmers.

In 2014 Qtrac began selling its in-house developed PDF comparison products. The two main products, DiffPDF (a GUI desktop application) and comparepdfcmd (a console command line tool) are both accurate and very fast. Between them these products sold into 61 countries worldwide.

On 25th October 2024, after 18 years in business, Qtrac ceased trading, a victim of the Digital River/MyCommerce scandal (see, e.g., The Register and Forum).

For many years we also produced a wide variety of free open source software, mostly small libraries and utilities created using many different programming languages. However, In view of the EU’s Cyber Resilience Act (CRA) and an abundance of caution, we have withdrawn all our free software. See our comments on the CRA.

Nowadays we write software for our own use and also contribute to other people’s open source software projects, code, documentation, or both.