ConnectedText ($40, 30-day free trial) is a personal wiki program. With it, you can very easily create wiki-style documents which can be as simple or as complex as you wish. This format is ideal for research notes, documentation of complex topics, authors, and any other project which involves a lot of information which is both interrelated and easily broken into multiple smaller topics.
ConnectedText is in general very easy to use, but it does require a small amount of learning. Rather than using a WYSIWYG editing interface, ConnectedText uses a plain text editor. To create a link, surround a word in double brackets: "[[Link]]". To boldface, use "**". To create levels of headers, you use the "=" sign, and so on. The actual appearance of the text to the user is determined by a Cascading Style Sheet. Three default styles are included, and anyone who knows CSS can create new formats or edit the existing ones.
After a few hours, ConnectedText's editing syntax becomes second nature, and it's much faster than using a graphical editing tool, especially if you're entering a lot of data with links. The user does not need to create a page before linking to it: Create a link on one page, then click on it, and a new page with that name will be created. Links for which no page yet exists are shown in bold, so it's easy to see what still needs to be done.
The true power of ConnectedText starts to become apparent if you delve deeper. Topics can have a tremendous amount of metadata associated with them--Categories (as many as you like) such as "Nations," "Cars," or "World Leaders,"; Properties (for example, you might wish to track population, land area, and GDP for topics about individual countries); "Related" topics (topics relevant to the current one but not explicitly linked in the text); and so on. ConnectedText supports the creation of plug-ins--executable code modules--in several languages, including Python, and the generation of graphical formulas using LaTeX. There are powerful commands which can be used to embed topics, or parts of topics, in others topics, creating dynamically generated pages. ConnectedText is one of those programs in which it takes only a short while to become productive, but there are enough advanced features to accommodate complex needs.
A few problems cropped up in my testing. Entering tables is one of the areas where the plain text interface makes things harder, not easier. Any tables beyond the simplest quickly become a frustrating exercise in entering text, switching to 'View' mode, then switching back to edit to try again. Although you can have multiple projects open, you cannot view two projects at the same time, side-by-side. You can export your project to HTML, plain text, or HTML Help (with Microsoft's free Help Compiler installed), but there is no 'Viewer' program to let you share your projects with others more easily. Further, one of the common uses for Wiki-style documents is collaboration, but ConnectedText is intended for use in a stand-alone computing environment.
I have personally been using ConnectedText for about four years now, and I have tried a wide range of other programs, including outliners, "text databases," and some of the many other wiki tools. ConnectedText has always had the best blend of features, functionality, and usability for me. I strongly recommend that anyone who works with "chunk style" data, especially if it is not easily placed into a purely hierarchical outline form, take a look at ConnectedText.