Implementing GZip requires a little more work then expected. It won't be available in 6.19, because I don't want to wait that long with the already implemented feature requests. I'll see what I can do for 6.20.
In the meantime, you could use PHP's output buffer feature to capture all the output and GZip them in PHP:
ob_start();
<your code>
$output = ob_get_contents();
ob_end_clean();
$go_gzip = false;
if (($encodings = $_SERVER["HTTP_ACCEPT_ENCODING"]) !== null) {
if (strpos($encodings, "gzip") !== false) {
$do_gzip = true;
}
}
if ($do_gzip) {
header("Content-Encoding: gzip");
print gzencode($output, 6);
} else {
print $output;
}