I'm working on a multicast dns implementation in OCaml. It's a library allowing one to build custom queries/responders, plus a conventional querier that can be used as a stub resolver for .local to get the resolver functionality of avahi.

My main motivation was to implement a service that publishes the addresses of containers and vms that I run on my workstation to my local network, but it gradually has grown into a full-blown implementation of RFC 6762, which has been fun.