The input method server comprises three related processes running together. The processes are htt, htt_xbe, and htt_server. One process controls the input method server properties, another controls the population of the input method server (that is, a “watchdog” process), and the third handles input methods of clients.
Usually, you don't need to know the details of these three processes. When htt is started, htt_xbe and htt_server are started automatically.