sorry for all these dump questions, but do I have to start manually that mDNS Responder of howl?
If you installed it by hand, then yes. You could of course make an rc script for it, or use an existing one. If you had an old .deb, you could have used the rc script for that.
Alternately, I would guess that the howl distribution has an example rc script.
Also, I just found 0.9.2 of howl and just try to compile it. Is that the version you used? I also found 0.9.5 and 0.9.6…
Anything > 0.9.5 should work. (including 0.9.6)