I’ve just started using TiddlyWiki for worldbuilding and it is such an excellent tool that I just had to post about it. If you haven’t heard of it, it is a free downloadable and portable personal wiki that can be used offline.
I love worldbuilding, but the problem with that is that I just want to keep on building. I get an idea and make a setting, then I have another idea that doesn’t fit with the setting we’re now using, or a sci-fi device while we’re playing fantasy, or something else that just doesn’t fit. So, I write it down for later. Using a basic Word document is fine, but it is static. Using a wiki allows you to link anything to anything else.