RMOO is a MOO client for the GNU Emacs text editor. It will run anywhere Emacs runs. RMOO allows you to edit notes, mail and code in separate Emacs buffers and then send them back to the MOO.
Emacs is the ultimate customisable programming environment, so implementing a MOO client in it gives you access to a wide range of useful tools to use when writing and editing for the MOO.
TkMOO is a MOO client implemented in the TCL scripting language. It will run anywhere the “wish” TCL/Tk interpreter is installed.
Note that you may need to edit the code to refer to a more modern version of wish before it will run.