An infinite canvas library that I can use in my drawing application prototypes. It's working already, performance is good, only misses the ability to sync with a server now.
https://github.com/Azeirah/note-taking-experimentation
It's in the infinite-canvas folder. Just open the index.html file and it should simply work, as there is no set-up needed yet.
Drag + left click = draw Drag + right click = pad the world
I'm not planning whatsoever to support or document this. It's open source, but I leave it at that.
One thing I noted with this is that window resizes seem to affect the stroke width. This is not a bug report, I'm just mentioning in case it's useful to you.