"AFAIK, it is entirely up to the server and the applications running on it to decide how and if a directory is rendered at any given URL. Just because I can get a document at http://someurl.com/documents/mydoc.txt doesn't mean I can get a directory at http://someurl.com/documents/. I might."

I inferred from his question (where he said, "http - standard apache index") that this was already not a problem. That he has a particular directory in mind which has a known directory listing format.

"Which module would you suggest for reliably getting the contents of a remote directory via HTTP?"

Personally I'd use Web::Magic, but I'm biased.

use 5.010;
use strict;
use PerlX::MethodCallWithBlock;

use Path::Class qw(file dir);
use Web::Magic -sub => 'web';
use XML::LibXML 2.0000;

my $listing     = URI->new('http://buzzword.org.uk/2012/');
my $destination = dir('/home/tai/tmp/downloaded/');

# Make sure destination directory exists.
$destination->mkpath;

web($listing)

    # Die if 404 or some other error
    -> assert_success
    
    # Find all the links on the page
    -> querySelectorAll('a[href]')
    
    # Skip uninteresting links
    -> grep {
        not (
            /Parent Directory/
            or $_->{href} =~ m{\?}  # has a query
            or $_->{href} =~ m{/$}  # ends in slash
        )
    }
    
    # Expand relative URI references to absolute URIs
    -> map {
        URI->new_abs($_->{href}, $listing)
    }
    
    # Save each to the destination directory
    -> foreach {
        # Figure out name of file to save as
        my $filename = $destination->file( [$_->path_segments]->[-1] )
+;
        
        # Log a message
        printf STDERR "Saving <%s> to '%s'\n", $_, $filename;
        
        # Save it!
        web($_)->save_as("$filename");
    }
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