HTML::HTML5::Parser parses the HTML into a DOM tree. It preserves all elements and all attributes. (The example I gave earlier showed filtering by the class="thead".)

Once the HTML is parsed, it's returned as an XML::LibXML::Document object, so you can manipulate it through object-oriented programming using more or less the same DOM API supported by desktop web browsers such as Internet Explorer, Firefox, Chrome, etc. Just using Perl instead of Javascript.

For example:

// Javascript
var links = document.getElementsByTagName('a');

for (var i = 0; i < links.length; i++) {
    alert(links[i].href);
}
[download]

# Perl
my $document = HTML::HTML5::Parser->load_html(location => $url);
my @links    = $document->getElementsByTagName('a');

for (my $i = 0; $i < @links; $i++) {
    warn($links[$i]{href});
}
[download]

The majority of HTML parsing modules work along the same lines.