Aura is actually no longer in development, according to posts from Vlado over at the Chaos Group forums. From the following Aura thread:
The situation is such that there is no-one here to take care of the development and support for Aura, so it is hanging in an indefinite state for now.
Hehe, no; we hope to be able to put together what we have so far and just release it as it is.
I am not sure what the last statement means. I am guessing it may go freeware like simcloth, maybe if we are lucky. I can’t see them releasing it as a commercial tool with no one there to handle development and support.