Having finally looked at the secondary log files for the Virtual Host, I discovered it's printing an error of
Undefined subroutine &Apache::Registry::handler called Apache::Registry.pm is definitely there, and everything runs fine without the PerlModule calls to Apache::DB and Apache::DProf. I was running via my benchmark script so didn't notice it was coming back with Internal Server Error, oops. The httpd.conf entries, which might get someone to call me an idiot, are: <VirtualHost *> DocumentRoot /var/www/elizium/html ServerName localhost ErrorLog /var/www/elizium/logs/error.log CustomLog /var/www/elizium/logs/access.log common <Perl> use lib '/var/www/elizium/cgi-bin', '/var/www/elizium/cgi-bin/lib', '/var/www/elizium/cgi-bin/plugins', '/var/www/elizium/conf'; </Perl> PerlModule Apache::DB PerlModule Apache::DProf PerlModule Apache::DBI PerlRequire /var/www/elizium/cgi-bin/startup.pl PerlFreshRestart On Alias /cgi-bin/ /var/www/elizium/cgi-bin/ <Location /cgi-bin> SetHandler perl-script PerlHandler Apache::Registry Options +ExecCGI PerlSendHeader On </Location> </VirtualHost> startup.pl just contains use CGI; use Data::Dumper qw(DumperX); Barbie.