I am trying out QML Designer using Qt Creator 2.0.1, but the designer tab is disabled when I create a new QML project.
Can QML be edited in designer mode like ui
files in C++?
In Qt Creator 2.0.1, the QML Designer is disabled by default. You'll need to enable it manually by going into Help -> About Plugins..., checking QmlDesigner, and then restarting Qt Creator. However, it is disabled for good reason.
You should really upgrade to at least Qt Creator 2.1.0, or to the just released 2.2 beta.
I'd suggest going for the beta, since its QML Design mode has seen a bit of a rewrite since the 2.1 version, and you would have a chance of providing feedback about any bugs before the final version is out.