The Z-machine Preservation Project is a Java implementation of the Z-machine (Java version >= 5 is required) specification. This Z-code interpreter can be run either as a standalone application or as an applet within a Web browser. It runs Interactive Fiction created by Infocom as well as those compiled with Inform, and targets all existing story file versions. Features include saving the game state, multimedia support (graphics, sound effects, meta data), colored and styled text, undo, and timed input as well as support for different languages. Games in the Inform 7 release format are supported as well (Treaty of Babel specification).
Yes, sequence diagrams will come next, since I have an immediate need for them. The plan is to include all UML 2 diagram types, structure diagrams are the ones that I am using to get my feet wet.