Yes, there is a method for PHP.
<?php
// We'll be outputting a PDF
header('Content-type: application/pdf');
// It will be called downloaded.pdf
header('Content-Disposition: attachment; filename="downloaded.pdf"');
// The PDF source is in original.pdf
readfile('original.pdf');
?>
Just an example from the PHP manual.
Of course you need to adjust a couple of things like setting the Content-Type to application/zip.
