http://www.emacswiki.org/cgi-bin/emacs-en/PerlLanguage
http://nschum.de/src/emacs/ # highlight-parenthese, company-mode, window-numbering-mode
http://coderepos.org/share/browser/lang/elisp # perl-completion
http://www.emacswiki.org/cgi-bin/wiki/Ye_Wenbin # some stuff for Perl
http://www.emacswiki.org/emacs/CPerlAutoName # cperl-auto-name

modes: cperl-mode, flymake, flymake-extensions, yasnippet, org-mode,..

REPL: in Sepia and PDE we have REPL's, but nice REPL is Stylish, but need perl 5.10 and Devel::REPL from jrockway's repositary (or test with Devel::REPL from CPAN, may be it already works), see screencast

;; To highlight a region between parenthesis
(setq show-paren-delay 0 show-paren-style 'expression)
(show-paren-mode 1)
(set-face-background 'show-paren-match-face "#efedd2")

Anyway emacswiki and emacs planet -- our friends