I've never done it but if I would attempt it, I would start by looking at Apache::PerlRun. Modelling from Apache::PerlRun, I would figure out how to capture the script's STDOUT (localizing STDOUT before the scripts run and re-opening STDOUT out on an IO::Scalar??). Once I have the scripts output in a scalar, then I would filter it. Sounds like a real pain ... I would give serious consideration to just using an iframe.