Hey guys, I'm new to MUD client development. My current client basically only supports ANSI colors (so sad!). I'm interested to find out where I can go to learn about the various popular protocols used to send out of band information (any text at all not meant for the end user's consumption).
http://www.mudstandards.org/ - not sure how active this site currently is but there is probably a bit of useful information on different protocols there http://www.zuggsoft.com/page.php?file=zm... - this goes over the MXP specification but not in great detail as far as implementation goes. I would check out the Developer's Forum on the same site for more info. (link is on the MXP page)
Although the latest version of MXP allows you to transmit out-of-band data, I believe it is only supported by CMUD. The majority of clients only use MXP for links and 24-bit colour, and as a result that's all that most muds use it for as well.
Instead I'd suggest either GMCP or MSDP - or better yet, allow script writers to add their own support.