Twenty years ago, when I was a DW consultant at Oracle. A part of the reporting system for a client, kind of a "two-level recursive meta" thing: PL/SQL that generated HTML/JS that, when clicking a link or button to drill down, called other HTML/JS generated by other PL/SQL procedures. Having built similar stuff in Delphi at my previous job, it felt pretty damn stone-age. (And "Visual" Source Safe didn't make that better.)