LWP (libwww-perl) and LWP::Simple http://search.cpan.org/dist/libwww-perl/
WWW::Mechanize - based on the LWP library http://search.cpan.org/dist/WWW-Mechanize/
Test::WWW::Mechanize http://search.cpan.org/dist/Test-WWW-Mechanize/
HTML::Lint http://search.cpan.org/dist/HTML-Lint/
Test::HTML::Lint http://search.cpan.org/dist/Test-HTML-Lint/
Test::HTML::Tidy http://search.cpan.org/dist/Test-HTML-Tidy/
