Post Syndicated from Lennart Poettering original http://0pointer.net/blog/projects/project-indiana-part2.html
In response to Darren Kenny:
On Linux (and FreeBSD) nss-mdns has been
providing decent low-level integration of mDNS at the nsswitch level for
ages. In fact it even predates Avahi by a few months. Porting it to Solaris
would have been almost trivial. And, Sun engineers even asked about nss-mdns,
so I am quite sure that Sun knew about this.
You claim that our C API was internal? I wonder who told you that. I
definitely did not. The API has been available on the Avahi web site for ages
and is relatively well documented , I wonder how anyone could
ever come to the opinion that it was “internal”. Regarding API stability: yes, I
said that we make no guarantees about API stability — but I also said it was
a top-priority for us to keep the API compatible. I think that is the best you
can get from any project of the Free Software community. If there is
something in an API that we later learn is irrecoverably broken or stupid by design, then
we take the freedom to replace that or remove it entirely. Oh, and even Sun
does things like that in Java, Just think of the Java 1.x
nss-mdns does not make any use of D-Bus. It never did, it never will.
GNOME never formally made the decision to go Avahi AFAIK. It’s just what
everyone uses because it is available on all distributions. Also, a lot of GNOME software
can also be compiled against HOWL/Bonjour.
Implementing the Avahi API on top of the Bonjour API is just crack. For a
crude comparison: this is like implementing a POSIX compatiblity layer on top
of the DOS API. Crack. Just crack. There is lot of functionality you can
*never* emulate in any reasonable way on top of the current Bonjour API:
properly integrated IPv4+IPv6 support, AVAHI_BROWSER_ALL_FOR_NOW, the fact that the Avahi API is
transaction-based, all the different flag definitions, and a lot more. From a
technical persepective emulating Avahi on top of Bonjour is not feasible, while
the other way round perfectly is.
Let’s also not forget that Avahi comes with a Bonjour compatibility layer,
which gets almost any Bonjour app working on top of Avahi. And in contrast your
Avahi-on-top-of-Bonjour stuff it is not inherently borked. Yes, our Bonjour compatibility layer is
not perfect, but should be very easy to fix if there should still be an
incompatibility left. And the API of that layer is of course as much set in
stone as the upstream Bonjour API. Oh, and you wouldn’t have to run two daemons instead of
just one. And you would only need to ship and maintain a single mDNS package.
Oh, and the compatibility layer would only be needed for the few remaing
applications that still use Bonjour exclusively, and not by the majority of
So, in effect you chose Bonjour because of its API and added some Avahi’sh
API on top and this all is totally crackish. If you’d have done it the other way round
you would have gotten both APIs as well, but the overall solution would not
have been totally crackish. And let’s not forget that Avahi is much more
complete than Bonjour. (Maybe except wide-area support, Federico!).
Anyway, my original rant was not about the way Sun makes its decision but
just about the fact that your Avahi-to-Bonjour-bridge is … crack! And that
Wow, six times crack in a single article.
 For a Free Software API at least.