OK. An ape replies...
AmigaInABox is just a preconfigured WinUAE WB environment, with lots of apps and stuff already installed, for lazy people.
Amithlon is an Amiga emulator, part of the AmigaOS XL package. Distribution has been interrupted, due to legal problems. Here is the author's statement
AmigaDE is the Amiga 'Digital Environment'. This is separate from the traditional Amiga OS. It is based on Tao Group's elate system, and is Amiga's digital age solution - different digital products all communicating and working together, thanks to hardware-independent software. All very Trekky.
The AmigaOne is a hardware specification for machines to be able to run AmigaOS4. Current Amigas may be upgraded to meet this specification. This is the one you and I are waiting for.