Magnus Manske <magnusmanske <at> googlemail.com> writes:
Or we do without any servers, at the expense of older browsers: http://0xfe.blogspot.com/2010/05/music-notation-with-html5-
canvas.html
After reading this thread, I was going to suggest this library as well. :) I have played around with it and I think it is quite nice for tablature, but it is probably not as good for traditional musicians? It's true that it has a non-standard notation but it is oriented towards editing as simple text, and it is entirely client side, which solves a lot of the other problems you have discussed.
The official site of that javascript library is http://vexflow.com/ (there are more examples and demos there). It uses an MIT license. As part of a Wikia hackathon last year I wrote a simple extension which adds one parser hook, loads that javascript library and renders notation from a wiki page. The downside is the "flash of unstyled text" effect that you get as the page loads, but it does work quite well and the extension is only ~100 lines of code, including the code for the editing box that I created so that you can do ajax/live edits. If anyone wants to check out a demo of that, I can send a link to my devbox...
Owen@wikia