All software is available free as in speech and free as in pizza under the MIT Open Source License.
For more information and examples please see Audiofile.cc
If you've made it this far you're actually interested in the project. For that I salute you. Below is a list of the most important things that could help move Audiofile forward. If you see something that inspires you to act please do.
The elements being painted to the canvas (clefs, notes, rests, accidentals) were all hand drawn by myself in canvas. I have implemented code which displays the beautiful Unicode characters for each of the musical elements. However it doesn't work consistently across all browsers and OS's (surprise :p ).
We should add the functionality to detect a browser/OS's font support and serve them the Unicode characters if they support it and fallback to the hand drawn elements if not. I've been considering using @font-face but we need a good open source musical font. Which brings me to...
Music as markup is a movement that is only just beginning. As we grow we are going to need a good quality font that we know is licensed appropriately. That is why I propose that we build our own! ;-)
Ideally it would be a font that can be used via @font-face to deliver the fonts to as many browser/OS combos as possible.