Quest Machine is a full-featured, extensible quest system that lets you add hand-written and procedurally-generated quests to your project.
No scripting required.
Procedurally-generated quests: Create unlimited quests at runtime based on the actual state of the game world. Your players will always have something interesting to do!
Hand-written quests: Create any type of quest you can imagine, using an elegant node-based editor. You're not locked into a limited set of archetypes.