Fretboard fingering diagrams for Arvo Part's Spiegel Im Spiegel. With these diagrams you can pretty much learn the piece without scores or tabs

https://mike-hoegeman.github.io/music/scores-etc/SpiegelImSpiegel/SpiegelDiagrams.html

updated with spiffier diagrams

Does anyone know how Greg Howard made his fretboard animations in his videos?

Example:

i haven't seen that before. Greg's learning materials are always phenomenal. this is no different. I have no clue how he did it, but i suspect with some kind of video editor

when i was talking with my friend about hacking up the diagram gadget. we mused about maybe putting a midi input capability into it. seeing that video demonstrates how that could be useful.
another possibility might be animating tablature from musicXML files. most music scoring programs export musicXML and musescore allows you to read midi files & output musicXML
so that might kill two birds with one stone if one is clever about it.

here's one someone did for the accordian which is pretty neat
https://bandochords.de/index.php?s=xmlplay