Hi.

I don't think they offer a completely free download but a 'free' trial version is available:

http://www.perlscriptingtool.com/pst/

You might also want to look at ActiveState's Visual Perl:

http://www.activestate.com/Products/Visual_Perl/

I would also look on SourceForge for related projects. They offer quite a bit of good stuff.
Hope this helps,
Cait.