Since my last post was about the horrible interface of Seed, I wanted to look in the other direction and talk about an MMO that really did things rights with their interface. That would be World of Warcraft.
Their default interface is slick, well-organized and very pretty. But, by far the best thing they have ever done with it was to build an API so that creative users could make their own mods and tweak the interface to their liking. This has led to an astounding number of addons which do everything from simply changing the look of the interface to adding in completely new functionality. And, in what I consider a stroke of genius, the programmers at Blizzard often take parts from the some of the more popular addons and integrate them into the default interface. That little button on the crafting menu that lets you make multiple items with one click? That was originally a user-created mod back in the beta test. The floating damage text? That was also a mod. Quick looting, visible buff timers, extra action bars just to name a few more.
The concept of facilitating easy access to the interface via various API options, hooks and slash commands, giving the users free reign and then studying what the users create to plug potentially game-breaking gaps and to further improve your own interface is just brilliant. There are still a lot of things I think that Blizzard should include in the default interface (moveable windows!? Hellooo!!!), but their controlled open-ness and willingness to change their game has led to the best MMOPW game interface I've ever seen. And I hope future companies look at this feature as one thing that Blizzard did incredibly-right, and plan on incorporating something similar in their own games.