Simple communication methods?

1

i 'm finding methods to do simple communication to another custom applications
it’s basically using flash client to control the target application while the target application will also have realtime feedback to affect the flash movie

now i find that I can send XML to a URL (in my case local host) for a specified port)
i’m wondering

  1. if there is other methods to send out data
  2. any actionscript to receive data ? like opening a socket? or any other method to get data/string from a location, and in what format and protocal?

thanks