Drag and Drop with MathML is possible?

Hi,

drag and drop with math isn't a very new [1, 2, 3]. But I'm couldn't find a
drag and drop tool that use MathML and is powered with Javascript. Try to do
it, see [4], but didn't work. Any help?

Thanks,
Raniere

[1] http://www.dragmath.bham.ac.uk/index.html
[2] https://github.com/jlabarbera11/TouchOfMath
[3] http://galvosukykla.lt/failai/coding/equation-exercise/proof-of-concept.html
[4] http://www.ime.unicamp.br/~ra092767/mathml.js/demos/demo-0.html