Options for rendering musicXML "in the browser"

commercial closed source "embeddable" options:

musescore.com (one pro license for whatever you want, $60/yr)

soundslice.com "$0.50/user/month" or "$50/month for free music websites" (when I checked)

open source:

abcweb: http://wim.vree.org/js/

vexflow itself doesn't "do" musicxml but here mentions some forks of it that do/might.

related: http://stackoverflow.com/a/27191517/32453