I've used ad-hoc test case generation using Prolog (MC/DC, all-permutations and other combinatorials) which is a quite natural application for Prolog. Around 20

I've used ad-hoc test case generation using Prolog (MC/DC, all-permutations and other combinatorials) which is a quite natural application for Prolog. Around 2005 I've also used Prolog to generate Java code for analysing/monitoring business processes based on formal business process descriptions on a research project for a Telco who went all-in on SOA. As part of that, I also started to develop decision procedures for static type checking of XML-manipulating programs, along with validators for common markup meta-languages (XSD and subsets). Many years ago I've also developed custom file parsing/business rules checking using Prolog. Plus, a couple ad-hoc parsers and DSLs. And, having developed 2 1/2 prolog engines so far, I'm planning to include ISO Prolog in my upcoming document storage/search system based on SGML, where Prolog is an excellent match since it's both an ISO standard (like SGML), and even has a binding to a document query language based on ISO/IEC 13250 (eg. the proposed "tolog" language, though alternatives were proposed and an ISO/IEC 13250 query language was never completed as a standard).