Recently I have shifted my focus from TwinNote to a new (or rather newly revised) alternative notation system called Clairnote. TwinNote will not be going away but I expect that I will put my future efforts into Clairnote rather than TwinNote. The TwinNote website has been effectively archived and moved to this new location:
twinnote.clairnote.org (Previously "clairnote.org/twinnote/")
You can learn more about Clairnote at clairnote.org.