aimage is the Advanced Disk Imager.
With Version 3.1 the aimage package has been removed from AFF and
re-packaged as a stand-alone install. This is to allow more rapid
development of aimage without impacting the use or certificate of
AFFLIB.
The current version of aimage is version 3.1. You can download it
from:
http://www.afflib.org/downloads/aimage-3.1.0.tar.gz.