Wow, mod_plsql looks really cool, I didn't know about it.
From the replies I think it mainly went out of favour because of lack of reactivity. I could port PageQL to C/Postgresl/Mysql, but I don't think it would be sufficient for a modern application, as reactivity is expected nowdays. Still, I keep it in mind to leave this kind of development as an option in the future.
HTML + SQL + imperative PL/SQL, running inside the database, right next to the data.