I have this:
<div id="results">
<?php include 'server.php'; ?>
</div>
which done a space in my html layout.

Server.php looks like:
<?php
//php processing...
//first echo:
echo '<h1>Serveur : '.$hostname.'</h1>';
//others echo...
?>
Why this space ? A solution ?
Verify that the file server.php isn’t in UTF-8 with BOM, and try removing the closing tag, ie :