Local Installation
By definition, any wiki software you run that's only on your computer is going to be personal. Not that you can't share your PC, but most of these solutions are meant to be simple engines for note-taking.

    TiddlyWiki Imagine a wiki that is one giant document. However, the sections are easily accessed not by scrolling but by instantly linking among the areas. In this case, those sections are called "tiddlers," which leads to the name TiddlyWiki. It's essentially an HTML document you can edit from within the browser, then use your browser to access it anytime you want, jumping from tiddler to tiddler as needed. If you put the TiddlyWiki file on a webpage you own, anyone can edit it, giving you some instant group wiki action if needed. If you want a version of TiddlyWiki that's already hosted online, TiddlySpace will provide it, though you will need to know some wiki markup to put it either of them to use.

    Zim Wiki This software isn't just for Windows. Linux users may need wikis more than anyone, and this tool lets a user start making notes instantly, creating new pages on the fly with "WikiWords" and some WYSIWYG tools. The Windows-only Linked Notes looks very similar. Both also have portable installers, so you can run them from a USB flash drive and take anywhere.

    Notational Velocity This free, open source, Mac-only note taker is for gear heads who never take their fingers off the keyboard. In fact, its Spartan interface doesn't seem particularly Mac-esque. It's all about taking quick notes and quickly finding them again.

    Springnote This isn't exactly local, but Web-based Springnote is a note-taking website that states right up front that it's "based on wiki." There are personal and group notebook abilities, even an iPhone app. It's much more geared toward sharing and group projects than a full blown wiki (though you can make a notebook public), so it's great for small groups. It's all WYSIWYG, making it simple for novices to master quickly.