[Orrin]

I use my own protocol, although it's similar to ATCP or MSDP in that it's just text inside a telnet subnegotiaition. I was hoping that a more generic standard protocol would emerge rather than me introducing yet another custom protocol with a very narrow use.

I would probably go with ATCP as that has good support in other clients and MSDP seems just a little too generic as is. Taking energy bars as an example, using ATCP you already have the char.vitals module which follows the pattern name:current/max name:current/max etc. which is super easy to parse into graphical bars on the client regardless of how many different stats the MUD uses or what they are called.