Although it's possible to use all features here by using only Win32::OLE module, DTS (being more specific, it's childs classes) provides a much easier interface (pure Perl) and (hopefully) a better documentation. Since it's build over Win32::OLE module, DTS will only work with Active Perl distribuition running in a Microsoft Windows operational system.
See the Introduction in Wiki for more information.
I have also an introdutory article about PerlDTS published on SQL Server Central website in http://www.sqlservercentral.com/articles/Perl/65025/.
Where is the source code?
If you're looking for the source code, click here. Otherwise, if you're looking for the traditional tarball with the source code, please download it from a CPAN repository or look for the distribution name in the website http://search.cpan.org to download it. I'll not duplicate the tarball here (the project website) and in CPAN.
Of course, since PerlDTS is pure Perl code, one can fetch all source code from the ZIP file of the PPM package.