I've been working on an A/UX emulator for the past few years, and just released v0.0.1 on github:https://github.com/pruten/shoebill
Shoebill is an all-new, BSD-licensed Macintosh II emulator designed from the ground up with the singular goal of running A/UX.
A/UX 1.x.x through 2.0.0 are supported currently, and 3.x.x support is in progress.
It's extremely buggy right now, very incomplete, and a little difficult to setup since you'll need to extract the A/UX kernel from your boot image (/unix).
Pro tip: (if you have an A/UX installation CD, you can boot directly from that.)
I'll work on getting up documentation in the near future. In the mean time, if anyone is so inclined and adventurous, you can try to get it running with a Macintosh II ROM, an A/UX installation CD image (v1 or v2), and the kernel from that CD.