@ Sema -
I just noticed Livid's reply to your post at:
http://forum.lividinstruments.com/discu ... server-com
It refers to a (redone) Off-Line editor I had not found before. This one seems to include all necessary materials (including JZZ.js and Jazz-Plugin), and works with the Web MIDI API. That is, It works (Win 10, 64-bit) in both Chrome and Opera (only).
Is there any benefit to us doing any further work (as we had proposed), or is the new Livid Off-Line version (which does not work On-Line for reasons they explain!) pretty much as good as it will get?
I presume so, but would appreciate your expert opinion.