Earlier quoted context omitted.
True, it's still a LAMP stack, migrating it to new PHP and MySQL (now MariaDB) versions every now & then, fixing a bug here and there, adding LetsEncrypt, switching from CVS to Mercurial to Git, etc. The last big feature I added was math formulas (2 years ago or so). This project really told me how important it is to leave comments for your future self - especially, if your future self hasn't touched some parts of th…
Do you already have a plan in place for what should happen to it after those 25+ years (universe willing)? Anyone to inherit it?
My experience is that it's very unlikely to find someone to carry such a site forward for decades -- everyone I met (except for 1 guy) loses interest after a few years.
Don't know if archive.org would carry a read-only version forward.