Maybe we should clear up the terminology slightly…
Zeroconf is the term for many technologies providing similar functionality.
“Avahi”/“Bonjour” is DNS-SD over mDNS to be concrete. I believe this to be the most useful one, but others would be very nice to have around too.
I believe this is what you are (primarily) asking for?
There are also others like SSDP, which is used for e.g. Philips Hue.
So… yeah, i appear to have implemented two varieties myself already. A well-abstracted API would have been much appreciated, and still would be a good upgrade.