Command matcher can filter out actions destined to failure (eg, closing a closed door) and reject them, leaving only unambiguous options (eg, if there are two doors, one open and one closed, 'close door' will unambiguously choose the open door.)
ITakeRules.HandleTake returns a value to indicate whether Take should proceed with the action or not. The great library of kuz, in database/static/testing, demonstrates why this may be useful.
List each link on their own line, with a bit more description, instead of having a single line list of links. Hiding link destinations following brightness rules will come when light and dark is implemented.
By implementing ILocaleDescriptionRules, a Thing can insert itself into the end of a room description, before other contents of the room are listed. It won't, then, be listed. Again demonstrated in the vast library of kuz.
'using RMUD;' is automatically inserted at the begining of every script. Look at how much nicer the code for the great library of kuz is without all the references to RMUD.
The great library of kuz is open for business. There are a nearly infinite variety of books available, and no limit on the size of your inventory. Take books until the server crashes.
Add nautical directions port, starboard, fore and aft, and clean up arrival messages to support them.
l is shorthand for look