`The iron-barred gate is a door. It is north of the Drawbridge and south of the Entrance Hall. It is closed and openable. Before entering the castle, try entering the gate instead. Before going inside in the Drawbridge, try going north instead. Understand "door" as the gate.`
However, what makes a command like "examine sword, then take it and give it to the wizard" complex is not the parsing, but the world model. What if examining the sword reveals an engraving saying "Never hand this to a wizard"? What happens to giving if taking fails? What if the wizard himself is holding the sword? What if he attacks anyone holding a weapon? Etc.
Writing a natural language command line interface seems a lot more straightforward.
https://groups.google.com/forum/#!topic/rec.arts.int-fiction...
Some more on how inform7 differs from more traditional interactive fiction systems:
http://www.onlamp.com/pub/a/onlamp/2006/06/08/inside-inform-...
As for this tool: I like it. I like the idea that it's simple, and that the author didn't let details like it being difficult to do "well" or "better" stand in his way. I've thought along the same lines many times, not so much "how did I do _ (solution often involves awk, sort, uniq et al) -- I'm too familiar with the command line for that, but rather: Jeez, you've got a smart phone. The one guaranteed interface that works is audio in/out. How hard could it be to deploy solid limited domain voice control coupled with a dead simple state-machine for doing stuff like "next song", "stop", "play", "accept call".
I wonder if these projects (there must have been projects, right, ever since the first uptake of mp3s) get the first part working, then some moron suggests that the user will expect to be able to do "play song such-and-such by such-and-such" -- and then it's no longer (strictly) limited domain, and that doesn't work, so the scrap the whole thing.
[edit: Some more on "newstyle" inform vs traditional IF:] "A Comparison of TADS 3 and Inform 7" http://brasslantern.org/writers/iftheory/tads3andi7.html
It can also parse sentences like the one with the sword and the wizard shown above. It's really not very difficult to achieve those things, as imperative sentences have pretty uniform characteristics that make the problem of parsing imperatives much easier than general parsing. As said in another comment, the bulk of the complexity of these systems is in the world model, not in the parsing.
A drawback is that, although the system works for several languages including English, the documentation for game developers/IF writers is only in Spanish at the moment. Collaboration for translating it to English would be very welcome.