When you talk about a personal wiki in any context, it does not take long for someone to mention "TiddlyWiki" as one of the best and most useful implementations of this concept. I have never had any serious reason to doubt such claims, even though I personally never took to any kind of TiddlyWiki because they seemed to "busy" to me. That's very subjective, I know. I was also worried by the fact that TiddlyWikis usually consist of just one file that needs to be opened in a browser. I am told that this does not present a big problem, as even large files can be navigated quickly, but it was a worry.
In any case, neither one of these would have been the biggest worry. I found out today that a TiddlyWiki does not keep track of all the tiddlers that refer to a renamed tiddler. Renaming a tiddler breaks all the links. But, one of the most important things of any wiki-like application for me is just this: the application keeps track of everything that links to a particular topic or entry, and I do not have to worry at all about what happens when I rename it. This seems to me an essential part of any "wiki." I am glad, therefore, that I never seriously tried to make TiddlyWiki work for me. I also think that anyone thinking about adopting TiddlyWiki should seriously think about this. Can you imagine what happens in a wiki with more than 10,000 entries, if you have to keep track of such changes.
1. https://github.com/Jermolene/TiddlyWiki5/issues/196, for instance.
2. Nor does this seem to be a superficial and easily fixed problem. I suppose it will eventually be solved ... but as far as I can tell, it hasn't so far.