use XML::RSS::Tools;
my $feed = 'http://rss.example.com/';
my $xslt = '/path/to/stylesheet';
my $rss  = XML::RSS::Tools->new;
if ($rss->rss_uri($feed) &&
    $rss->xsl_file($xslt) &&
    $rss->transform)
{
    print $rss->as_string
} else {
    print $rss->as_string('error')
};

##</code><code>##

use XML::Feed;
my $feed = XML::Feed->parse(URI->new($feed))
    or die XML::Feed->errstr;
for my $entry ($feed->entries) {
    # extract info from entry and generate output
}