My database publishing system's programming language is both English and German. While programmers usually prefer the English interface, a rather large percentage of my users prefer the German one. (en: https://speedata.github.io/publisher/manual/index.html, de: https://speedata.github.io/publisher/manual/index-de.html)

There is also for example ConTeXt (http://wiki.contextgarden.net) - a typesetting language similar to LaTeX, which supports commands in English, Dutch and German.