A Multi-User Dungeon (MUD) in Lua?

["Kurt Nordstrom" <kurt@...>]

Hey Lua people,

I am wanting to code as a hobby project, a sort of multi-user
dungeon/dimension/whatever (MUD) game, using Lua as the in-game "softcode"
development layer.  In actually, it would probably be closest in feel to a
Mush/Mux/Moo.  Anyhow...

I could use some ideas on how to best structure the in game Lua objects. 
My intention is to have a "master" object that will interact with the C++
game driver, and control several player-created objects, to which Lua
functions can be added in-game by users.

One of my concerns here is security.  I want the master object to be able
to arbitrarily call the game objects, but I don't want the game objects to
be able to see or affect the master object.  Can anybody suggest a good
way of doing this?  One possibility I thought was to possibly give all of
the game objects a different environment, in which the master object would
not be a part of.  The other would be to enact some sort of privacy scheme
using closures like detailed in the Programming in Lua book.

Does anybody here have advice or suggestions for how I might go about
this?  I'm looking for the simplest and most straightforward route.

Thanks,

-Kurt