Like thomas895 said, all you need is ssh2 access, no X11 required. Once you connect, you change the shebang for the CGI to <C>#!/usr/bin/perl -d and you set perl5db.pl RemotePort option to localhost:666119 ...

http://docs.activestate.com/komodo/4.4/debugperl.html# Debugging Perl

http://community.activestate.com/forum/help-interactive-debugging-windows# Help: Interactive debugging on Windows

http://plosquare.blogspot.com/2009/04/debugging-modperl-applications-with.html# Debugging mod_perl with EPIC

http://www252.pair.com/comdog/mastering_perl/Chapters/04.debugger.html# Mastering Perl: Debugging Perl

http://wiki.eprints.org/w/EclipseEpicPerlDebug

Enabling GUI Debugging under Mod_Perl

http://books.google.com/books?id=UDUmoHOUXiMC&pg=PA142&lpg=PA142&dq=perl5db+Remote+Port+tutorial&source=bl&ots=_7fyyfZ2VK&sig=IBHqYwf7yXF0JKKx0Oh2VsZF9v0&hl=en

Devel::ebug, ebug_http, ebug-client, ebug-server