#! perl -w

use strict;
use Data::Dump qw(dump);

my (@urls, @ids, @titles) = ();

while (<DATA>) {
    my ($url, $id, $title) = ($_ =~ m|<h6 class="project-title"><a href="(/projects/(\d+)/.+?\?ref=discovery)" target="">(.+?)</a></h6>|o );
    push @urls, $url;
    push @ids, $id;
    push @titles, $title;
}

dump @urls, @ids, @titles;

__END__
<h6 class="project-title"><a href="/projects/1956727289/how-to-build-a-spaceship?ref=discovery" target="">How To Build A Spaceship</a></h6><p class="project-byline">Rohan Sinha</p>