Lighttpd

lighttpd is a web server.

Proxy

If you want to service something on port 80 that's provided by an application serving at port 9030 then you can do this:

$HTTP["url"] =~ "^/tor/" {
    proxy.server = ( "" =>
        (
            (
                "host" => "127.0.0.1",
                "port" => 9030
            )
        )
    )
}

This example assumes that any content asked for on port 80 which starts with /tor/ is to be proxied from localhost port 9030 (this example is intended to serve Tor directory requests).