I probably have an answer for this one once the OP responds, don't know why it was closed.
I remember commenting in another question, that was being closed, like this:
Juju is free to use. The Juju server runs on any system with Ubuntu Server installed from your laptop to private cloud to any certified public clouds. The client current runs on any Ubuntu system, Mac OS X or Windows.
With Juju and Ubuntu One you must remember that they are on-topic, even if they are on Windows.