AweMUD is a MUD server for use with fantasy-settings. Features include fully dynamic objects and characters, an advanced scripting system, and custom worlds. The engine will eventually have completely interactive rooms (items can be placed under benches, doors can be destroyed), complex magick, and interactive NPCs.
Myth2 is an implementation of a binary tree and used to run an 'interactive story'. The user traverses down the tree and at each node is given a bit of story and two options to choose which path to follow. If there is no story after the option, the user is given the chance to add to the story. It is written in PHP 4 and uses MySQL for the backend. Output is fully XHTML 1.0 Transitional compatible and fairly flexible.