Well, the classic editor is gedi or gedi-lite

perl -MTk -e " tkinit->TextEdit->pack; MainLoop "
[download]

perl -MTk -e " tkinit->Scrolled( q/TextEdit/ )->pack; MainLoop "
[download]

but its broke :)

update: still broke since 2005 , yuck, Bug #13807 for Tk: Bug in getOpenFile/getSaveFile

http://search.cpan.org/src/SREZIC/Tk-804.030/Tk/TextEdit.pm

http://search.cpan.org/~srezic/Tk-804.030/pod/TextUndo.pod

perl -MTk -e " my $te = tkinit->Scrolled( q/TextUndo/ )->pack; $te->Lo
+ad( q/filename/ ); MainLoop "
[download]

As usual, there is also example in the widget demo, widget - Demonstration of Perl/Tk widgets