Perl mode helps you write Perl code. Since the Perl syntax is very hairy, Perl mode has to work extra hard to try and avoid messing up syntax hilighting.
If you are having problems because lone apostrophes (’) confuse Perl mode, add a #’ at the end of the offending line. That helps a lot.
If you are having problems with perldoc comments in Emacs 20, remember that font-lock operates only on lines. Font-locking will be correct when you open the file, but you can mess it up. Use
‘M-g’ to refontify the current block of code. That should fix most problems.
If you see no colors at all, maybe you have font-lock switched off? In Emacs, try
‘M-x global-font-lock-mode’. If that helps, add the following to your ~/.emacs file: