lwresd was present long ago in Debian 4, acompanied by the libc library plugin libnss_lwres. It was intended to be a simpler cache than a standard name server, but it never gained wide adoption. Because it offered no significant advantages over using a DNS server like named directly. It was removed from BIND9 after version 9.11.
I have a few ideas on how to use it over Unix domain sockets to unlock new features. With some significant modifications to the original concept, it may make sense to revive the lwresd daemon.