One of my perennial problems with PKM, and I’m sure other peoples’, is surfacing relevant information in a meaningful way. I like to liberally tag stuff with multiple, ad hoc, hierarchical tags within my Denote notes, and though I keep my Denote keywords to a reasonably strict set, I still found myself needing a method of viewing and select them in a visibly easy manner. I spent a bit of time this morning hacking a bit of Elisp code together, which seems to work reasonably well:

https://github.com/Cthimothy/denote-keyword-browser

I might add some sort of sorting in future.