title: how to implement “server push ” on apache-php-mysql machine?
body: <p>here is the question:
      when one user upload something to the server(apache).
  the server will " push " the request data to all the users .
    and I don't want to use "ajax" or javascript "timeout reload"。
  It costs a lot 
    so, Is there any javascript lib can implement the "server push" technology?</p>