SocketMUD(tm) is released under Public Domain. Parts of the code was 
written by Erwin Andreasen (http://www.andreasen.org/), and even though
the code written by Erwin is also public domain, it would be nice if any 
user of this codebase would keep the credits for Erwin. The copyover and 
buffer code is inspired, converted and sometimes copy/pasted from the code 
found on his website.

WickedMUD includes the MTH snippet by Igor van den Hoven which is public
domain.