I also don't love the conventional handwritten aesthetic you often see for jazz fonts. For a project I've been working on, I ended up pulling the handful of chord symbol glyphs out of MuseScore's Leland Text font and adjusting them for use in the UI since I couldn't find a suitable option out there.
For just chord analysis, there's "Harte notation", which is meant to be unambiguous representation of the notes (https://ismir2005.ismir.net/proceedings/1080.pdf). That obviously doesn't get you all of the additional information necessary for engraving and full representation of the music, but there are research datasets available using it like https://github.com/smashub/choco. I've also used the https://github.com/MarkGotham/When-in-Rome dataset for some analysis work, but again that's not 100% what you're looking for.
You might like the "iReal Pro" app for the replacement and transposition of jazz standards on your tablet. It's pretty great for that use case versus camera scans.
I had attempted to create a pass for my local library in the past, but never got a working barcode, and this post helped me to understand the issues I was hitting.
I was able to adapt the OP's shell script to generate a working Codabar image (after I figured out that my local library used "A" and "T" as beginning and end markers) that matched the physical card exactly, and there was enough useful metadata for me to piece together a working pass using that barcode as a store card's background image. I ended up using the Pass2U Wallet iOS app directly, rather than hacking around signing keys, but found the documented process helpful.
That's essentially what https://krypt.co/ is...I've used Yubikeys in the past, but have been on Krypton for maybe the past year or so. No problems with it at all, aside from GitHub recently (within the past couple of weeks) not recognizing the authorization despite it working just fine elsewhere. I haven't had a chance to dive deeper into why.
Tiddlywiki is what I use to manage my own personal Zettelkasten as well; it's pretty well suited for the task. There's a bit of ugliness when renaming Tiddlers, but for a lot of inter-related topics, I add an automatically-generated list of backlinks like this:
I prefer using the [United Nations Code for Trade and Transport Locations](http://www.unece.org/cefact/locode/service/location.html) (UN/LOCODE) value based on the address of the host's data center. It covers more specific locations than something like the IATA airport codes, and is still a well defined standard.
The workaround for 1) was already posted, but for 2), you can use Vimium's "insert mode" by pressing `i` to do the same thing. I use it regularly for Reddit with the enhancement suite.
So, I've skimmed through most of the paper, and it seems like a bit of an apples to oranges comparison. My understanding is that GV2 is an extension to jGit that essentially performs GC on the repo (or more accurately waits to encrypt until post-GC), and then transparently encrypts everything altogether, rather than utilizing clean/smudge filters to encrypt files individually like the tools it's comparing itself to. It's funny that the author dismissed git-remote-gcrypt as being "under development" even though it's a much closer comparison to GV2.
The paper mentions that it's measuring the worst-case scenario for the clean/smudge filter-style tools as it's much more likely that you only need to protect a few files and not the entire repository, but I didn't see how the second section actually reflected this more-realistic scenario. I'm not saying that encrypting the entire repository is bad, but the overhead of using filters to encrypt the entire repository is a documented/known limitation of the other tools...so it seems a little odd to gloss over that.
Side note, stuff like "This process is repeated a total of 10 iterations for an ample sample size to draw statistical conclusions." worries me, but that's another conversation.
Overall though, glad to see more research in this area, and it sounds like GV2 might be a decent solution for people looking to protect their data in certain scenarios.
Cool to run across a mention of one of my projects (transcrypt) out in the wild. I do like that blackbox isn't tied to just Git, and uses GPG...but that can also be difficult for adoption if GPG isn't a familiar tool on your team.