when i need to scrap a webpage, i use phpQuery (http://code.google.com/p/phpquery/), it's dead simple if you have experience with jQuery and i get all the benefits of a server-side programming language.
For Perl you can use Web::Query (but don't use the default HTML::TreeBuilder::XPath with it, it's extremely slow - use http://search.cpan.org/dist/HTML-TreeBuilder-LibXML/), or Mojo::DOM (part of Mojolicious: http://mojolicio.us/). Both use the nowdays standard CSS selectors for comfortable handling.
JavaScript can be scraped using WWW::Mechanize::Plugin::JavaScript or even WWW::Mechanize::Firefox).
