Hi George,

It depends how you want to approach your development. If you are comfortable setting up the environment yourself and maintaining it, then check the downloads available at the top of this page.

If you require hosting, then look at some of the founders which provide that service.

John

Hi George, if you want to start straight up, learning pool has already a hosted Adapt Authoring tool with some added functions.You can sign up for a 7 day trial as well. 

If you want to have the authoring tool locally, it's pretty easy as well. Just follow the instructions here.