Mumble supports querying server information by sending a ping packet to the target server. This includes: server version, currently connected users, max users allowed, allowed bandwidth. This implementation doesn't require anything on the server side, and will work on any server.
Read more about it here.
<?php
use xPaw\Mumble;
// require or your favourite autoloader
require __DIR__ . '/MumblePing.php';
$Info = MumblePing( 'example.com', 64738 );
if( $Info === false )
{
echo 'Ping failed.';
}
else
{
echo 'Users: ' . $Info[ 'Users' ] . ' / ' . $Info[ 'MaxUsers' ] . '<br>';
echo 'Version: ' . $Info[ 'Version' ] . '<br>';
echo 'Bandwidth: ' . $Info[ 'Bandwidth' ] . ' (bytes)<br>';
}