There are many Dahlgren engraving systems running with S-100 control crates. The boards are mostly Solid State Music whitelabels, except for the actual tool driving boards. They don't break often, but we do sometimes get requests to fix them.
Other S-100 boxes still exist, mostly being used by small old companies who are, frankly, in the "old owner's kids are't going to take this over" death spiral. Whatever they're doing with S-100 still works for them, so they keep running it.
We've got customers running PDP-8s and PDP-11s controlling old CNC machines, so S-100 isn't the oldest thing we still service. I also know of a pile of 286s helping make some super cutting edge silicon...
Thank you for confirming my hunch. Besides being clever from a technical perspective those systems were also designed in ways that make your average kitchen appliance look flimsy. You could probably drop one from a first floor, end up with a damaged pavement, a fine and and working system ;)
From a longevity perspective that stuff absolutely rocks, much like I'd much rather have a car from the 90's than one built today. The 90's one will outlive me, the one built today will need at least one replacement.
There's a pretty good hobbyist community around S-100, a fair number of folks are designing hobbyist-level new boards and such. A lot of that is centered around the following site:
s100computers.com
Some of their designs are...weird...and often "that's not a bug, we like it like that" is what you'll get for pointing out actual design issues...but! it's still cool to see people hacking on it.
The floppy drives of early Compaq PCs were rated/tested for a really high number of insertions/ejections. You'd have to be doing nothing BUT inserting/ejecting floppies 24/7 to even get close to the rated limit.
Some beancounter at Compaq realizes they're overpaying. They lower the rated limit of insertions/ejections by a couple orders of magnitude and let the savings flow through to the profit line with the customer none the wiser. Didn't help against Dell and the other cheaper PC manufacturers though.
As far as production use? Not sure since the S100 bus is less compact and more expensive than many newer designs.
Is anybody on HN aware of S100 systems used in production today?