On building tools in muds
In commercial terms, one of the things to keep in mind is that there are more users than builders in the market to sell to. There are more Quake players than Quake builders, to use an example, and Quake’s tools allow as-complete alteration of the Quake environment as any MUD-based system I have seen (more than virtually any template-based architecture, such as Diku-derived muds, certainly).
One thing to note is that muds themselves do a lousy job of providing these tools to the general public, in that the interfaces and tools tend to be obtuse and difficult. Since the mud community tends to be far more technically proficient than the general public, we take it in stride. Even then number of competent users of MUSHcode, LPC, and even of Diku area files is low compared to the total mudding population. But the general public will find @dig or OLC on a Diku hopelessly difficult, and it isn’t suitable for a mass market product. All the major graphical systems currently in development are intended for the mass market.
(Yes, I know there are several hobbyist ventures working on this; I don’t count them as major because they are in general not capable of devoting the amount of time, resources, and money to the task).