Your idea of plug-ins in real-time would be very interesting, Sibuna. I don\'t know if it really exists in another mmorpg.
It would need to solve several problems, like
1) what kind of source language would be permitted ? We wouldn\'t want malicious code to be uploaded to whatever system is used for the pug-ins. Then, the behaviour should be checked against cheating of course. Thus, only some specific world properties could be modified by the plugin in a controlled way.
2) where would it be uploaded ? In several ways, the plug-in is in fact a client in the world. Since the world is persistent, it cannot remain on the user\'s client. The ideal place would be the server, but it has only limited power whereas user count could be virtually illimited (even if they cannot log all at the same time, all their plug-ins should be there).
Another solution is to have plug-in farms, several systems acting as permanent clients. Once there is no more room/power for additional plug-ins, the farm would only have to grow.
With the additional difficulty that they should be replicated like the servers (for reasonable ping distance).
3) Plug-ins would have to be reviewed by some authority before being inserted into the world, because it is shared among the community. For instance, if you want to build your house somewhere, you need to acquire a property before.
Who will handle this job ? Voting ? Definitely not administrator who won\'t have the time for this (admin\'s, tell me if I am wrong
).
There might be other issues, but the principle is quite appealing, and might be worth the effort.
Look for instance some 3rd-party add-ons that exist for Morrowind and imagine the same for an mmorpg
