Genius has done a lot of work on annotation pinning. I remember hearing Tom Lehman discuss it in their dev meetup series when they expanded to annotating the w

Genius has done a lot of work on annotation pinning. I remember hearing Tom Lehman discuss it in their dev meetup series when they expanded to annotating the whole web. Still, I'm not sure that it actually took off on the greater web as lately it seems they're doubling down on rap content and industry connections. I haven't dug into how the standard addresses all of its edge cases yet, but I hope that it handles pinning well ie, if the underlying text is edited or deleted and it's unclear whether the annotation should persist.