I wonder if any ANS are still being used in anything beyond a hobby server.

I would run an ANS if I had one. Most people seem to prefer running Linux, but I'd run the original AIX and get some kind of web server rigged up.

You mean like the ANS 500 running (patched) AIX running classilla.org and floodgap.com?

Yes, it's 4.1.5, though I hacked it a lot for security reasons. It'll still be in service for awhile longer, though I'm having trouble getting things to compile with the ancient gcc 2 on it (and dynamic linking in that version of AIX is iffy, so everything is statically linked and I freak out the linker every time I do things like rebuild sendmail or named). Still, almost 13 years of service.