I recently tried to submit a package for mDNSResponder to AUR and it was rejected, saying that mDNSResponder is on the blacklist, but after some searching, I wasn't able to find any reference to it in the repositories or the blacklist reason. I realize that avahi provides the same functionality, but I'm willing to support MDNSR and it has become an optional dependency for Netatalk's newest alpha, so I would like to be able to link against it. The open-source package itself isn't the best-supported by Apple, but with a little work it's perfectly usable and provides the "official" solution; the IETF has asked Apple to submit mDNS as a standards track RFC [http://files.multicastdns.org/draft-cheshire-dnsext-multicastdns.txt]. The fact that it's lightweight (184KiB, no deps) doesn't hurt either. See the PKGBUILD at: https://bbs.archlinux.org/viewtopic.php?pid=1088978