Personal Knowledge Management Systems (PKMS)

I don't use some of them nearly enough, but I really like Zim Wiki on desktop/laptop for the ability to link to different files in my notes. For on the go, I tend to use Joplin right now as I like that it's open source & relatively easy to sync between my PC & phone.

I've dabbled a little with TiddlyWiki, but I feel like I need to learn more to really customize it more to my tastes. I've also been meaning to try running DokuWiki from a flash drive, as I like the wiki format a lot, but I feel like it may be a bit overkill.

I've seen some mention of Evernote & Obsidian here, but I've not used those personally. Also sorry if personal wikis are out of scope for this community, they're just among the first to come to mind when I read the name & sidebar!