PSPad uses Synedit. There are main 2 version - ANSI and Unicode SynEdit. PSpad uses Synedit one.
I try to look for differences in Perl highlighter used in Perl-Ide and highlighter used in Synedit used by PSPad -- <http://forum.pspad.com/read.php?2,48158,48166> PSPad freeware editor http://www.pspad.com
