TiddlyWiki comes in at the “not very many people know about it” department. Touted as a “reusable non-linear personal notebook”, TiddlyWiki is a quick and dirty, light-weight, and portable wiki application.

It’s always nice to be suprised by seemingly simple applications. TiddlyWiki has the basic features of modern Wikis: inline editing, markup formatting, ability to add HTML in entries, and easy save and load. The wiki aspect revolves around a tiddler, which is nothing more than a typical entry in any other wiki system. However, TiddlyWiki has so much AJAX embedded goodness that I don’t think you need to even do a single pageload except for the initial one.

When you click on a tiddler, it instantly pops up in the next available space in the main column. This is where the non-linear notebook part comes in–you can open up any number of tiddlers, which will all collate into one column. After leisurely perusing these, you can close any number of them easily.

Editing can be done inline with a single click of a button. Naturally, the edit box instantly pops up. Links from one tiddler to another are automatically parsed, based on the title of the tiddlers.

If you need a heavy-weight wiki application, TiddlyWiki might not be for you. But, if you just want a simple and easy to edit notebook to jot down ideas, TiddlyWiki beats out the competitors with its sheer speed.

So you may be wondering how TiddlyWiki installs. For many wiki systems, installation is a headache. When you click on the DownloadSoftware tiddly on the main page, you’ll be greeted with the fact that you’ve already downloaded the software. All of TiddlyWiki’s code is contained in the HTML file! You simply need to download an empty TiddlyWiki right to your computer, and you can instantly start editing. Now that’s what I call a painless install.

If you’re still not comfortable doing that, you could go for their hosted service at tiddlyspot.