For an individual, I used to use WikidPad and quite like it. Source: about 1 year ago

There also are "serverless" wikis, like http://tiddlywiki.com/ (can be run as a standalone desktop app - see in the bottom, or Wiki on a Stick, or WikiPad. Source: about 1 year ago

Wikidpad is quite functional. It's not the prettiest but it does its job. I don't know if or how you can implement images. But it's free and maybe worth a try. Source: over 1 year ago

Is it this one? http://wikidpad.sourceforge.net/ Also is it on mobile, and does it support images? Source: almost 2 years ago

If your work is not published its very likely to be removed by a mod on Wikipedia, but when it comes to organizing your world, a personal wiki is by far the best way to do so. There are lots of tools out there, both free and premium. I would recommend doing some research on all of the suggestions in this thread and find what works for you. Wikidpad is a free desktop wiki that's super handy when you just want to... Source: almost 2 years ago

You might find the following useful : Visual Understanding Environment - https://vue.tufts.edu/ Came across this in another thread recently - https://quarto.org/. - Source: Hacker News / 5 months ago

I use this for drawing "graphs" in the formal math sense like you're looking for: https://vue.tufts.edu/. Source: about 2 years ago

There are a number of free and commercial softwares developed for diagrams, flowcharts, and mind mapping with similar features. I haven't used them in a while, but in the past I've liked yEd and VUE. Both are free and support multiple platforms. Source: over 2 years ago

The site is working for me ( https://vue.tufts.edu ) as is the download, so it was probably a temporary glitch. Source: almost 3 years ago

I think your best bet may be Visual Understanding Environment (VUE). I can't say for sure if it will store or play videos but they make a big deal about "digital media" on their website. Source: almost 3 years ago