[Milawe]

Almost all of the 2nd generation MMOs use this type of leveling, and our latest project supports an extensive system for what you describe. (We simply don't call it questing because I personally feel that quests should be epic. That's kind of irrelevent for this discussion, I guess!)

But you can check out any of the modern MMOs to see how they do it, or you can come visit and see how we did it.