If you want other GPL software, there's Yet Another Web Portal System, and its derivatives WebApp and Poas. Out of these three WebApp seems to have the largest user base, and it has a semi-automatic install script.
Most of these are complete member site applications encompassing multiple scripts. If you just want some perl scripts that you can use to put together your own flavor of community check out Extropia.com for several open source web apps you can use for your site.
P.S. YAWPS, WebAPP, and POAS are all 100% Perl with no DB required.