Hello Gary,
The beta version doesn't require a registration with a license key since it's in a beta stage and freely available. In order to install Viewer for Mac download the dmg file on your Mac computer and double click/run it. This will invoke a window where you should drag the program icon to the Apps icon folder which will copy/install the files to your Applications. You can then run Viewer from there.
Any help at a basic level would be very helpful...
Since the beta Viewer is currently limited in functionality we are not proving extensive documentation for it. Rather, everything that you need to get started is covered in this
blog post. By the time we release the final version which is going to have more features than these initial beta releases we will also provide complete documentation.
Hope that helps.