When the app store first launched I would go searching for weird things, as time went on the amount of weirdness I would come across has gone way down. That's part of why I started the blog, to get some of that back.
YYZ is what I called my unfinished, unreleased Z-machine implementation. I was thinking about using it in an iOS app, so I wrote it in Objective-C, though I found that language wasn't a big improvement over C. I did get it far enough to start running Zork I, but I didn't implement saving and loading yet.
I noticed that some of the many Z-machine interpreters were named after magic words appearing in Zork, and I like Rush, so I picked a word that was reminiscent of "xyzzy".
