"telnet" could have two different meanings, 1. a comm. protocol, 2. a client-side utility uses telnet protocol. hyper terminal is a terminal simulation program that can use various protocols. these two do not stay well side by side.
what are you asking? you have a server listening on port 23 and want to find what client you can use? too many too list. or you what to find the ways to authenticate a user remotely?