Not to keep it in Perl, specifically, but to keep it entirely on the server. There is a reluctance to make any feature of the site depend on Javascript, or any other browser-side technology (other than HTML and CSS).

Just wondering... Could one avoid the full page reloads that are needed for voting, even without AJAX, by using... Iframes? I realize that Iframes are bad and deprecated and all, but they might be suited for this job:

Just put a "++" and a "--" button into an iframe above every post. Of course it would need some more requests to initially load all these extra frames, but that doesn't need any database access, and connection caching should mitigate most of the overhead.