And yes, I really do know and do all those things mentionned on my site ;-)
What software powers it?
The diary is powered by a program I wrote called "noNews" and the wiki is "noWiki". Both are code that I maintain as part of my Noink2 project. See http://www.geekcomix.com/noink2/
What is a "Wiki?"
It's a collaborative web-site creation engine. However, I have mine locked down so that only I and some editors can edit it. Basically, I'm using a wiki because I can create and edit online documents very quickly and easily (and I am a very lazy man ;-)