Check out the Common Questions section on Adobe's Edge Animate page.
As of right now, it says, "Edge Animate CC is available exclusively via Adobe Creative Cloud."
So it seems that you'll have to subscribe. CC membership for a single app is just $20/month. Not a huge price to support people who created the software that helps you.
I think it used to be free. I discovered it and started using it in the last few weeks, so I don't know the history well. I don't remember where, but somehwere in this video from 2012, Paul Trani talked about it being free. Something like if you cancel your CC membership, you can continue to use it. But that's old information and based on Adobe's site, it doesn't seem to be true anymore.
I do have one question that I don't have an answer to though. If you go to subscribe for a single app, Edge Animate is not in the list:
I think that once you subscribe, it will be available to download, but I'm not 100% sure. If it were my money on the line, I would make sure of that first.
For your information, if you are a student, you should be able to get the student rate provided you can get a proof of being a student from your school.