It seems that MusicXml is getting more support by popular notation software like Finale and Overture, but do you know how to play MusicXML directly from the browser?
MediaRain provides this web-based software now, but it's commercialware and seems to take a lot resources. [mediarain.com...] (see the demo)
Myriad makes a free plug-in for IE and firefox too, but users have to pre-install it, and the plugin doesn't work quite good. Sometimes, music just can't be played and zoom function fails to work all the time. (take a look: [myriad-online.com...] )
That's all the choices I know now. So, i'm wondering if there's more alternatives?
Also, do you think it's worth making a website that uses MusicXML?
unfortunately quicktime doesn't support musicxml so far.
I'd say MusicXML is more for music professional rather than ordinary music listeners. It has a strong cross-platform compatibility and many big software can import these files. But this can actually be done by midi files too, so I don't really know why people need it.