I wrote:

> The term 'caching DNS' doesn't actually mean anything.[1] All DNS software
> _caches_; even the stub resolver in glibc caches.

            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Well, probably I exaggerate. The stub resolver (Linux DNS client), upon
review, appears to be just about the only piece of software in the chain
that does _not_ cache. But pretty much any other definitely does, even
nscd, dproxy, dnsmasq, pdnsd, etc.