[1] Tech report: https://cpsc.yale.edu/sites/default/files/files/tr237.pdf
[2] There have been attempts to build declarative debuggers for other languages but for one reason or another (complexity, space use, incomplete coverage of the language, ...) they don't appear to get used very widely. Shapiro's setup is beautifully simple for what it does.
Here "declarative" means that you have a model in mind ("model" in the sense of logic, i.e., you expect your predicates to hold of particular arguments) and the tool helps you explore the divergence between what you wrote and what you intended. Thinking this way means you can completely ignore the details of SLD-NF resolution (the details of the Prolog implementation)... I mean, it's unlikely to be perfect in practice for any number of reasons, but I find it very disappointing that we don't dream like this any more.