[gabelschlager]

I didn't build it myself, but I maintained one for a while as part of a student job.

The website itself was hosting various resources for researchers, etc. Each resource was annotated via a specific XML format and XSLT was used to dynamically create HTML pages, as well as to transform the XML files into various other file formats.

The by far biggest problem was, and still is, that XSLT is very verbose and not well-maintainable. Small changes here and there were possible, but larger changes almost always required rewriting the entire stylesheet. On top of that, the XML format got bigger and bigger as well (as it was used and modified by Universities across Europe), edge cases were added, etc., that did not help when it came to writing the XSLT stylesheets, but that's a different problem. We also had to switch to XSLT 3.0 at some point and had to render the HTML server-side, since browsers don't support anything beyond XSLT 1.0.

Overall, I still kind of enjoyed working with it. For complex XML, it was by far the easiest way to work with them.