This hint describes how I got my Gentoo box streaming tunes to my Powerbook, having been inspired (but not particularly helped) by this hint, which isn't particularly clear and didn't seem the best way of doing things. NOTE: This stuff will mostly need to be done as root, or using sudo.
First, you need to install DAAPD. This is the server for Apple's Digital Audio Access protocol, and is what tells iTunes what songs are available and streams them. Installation instructions are on the site, but on Gentoo you'll just need to do a variant of emerge daapd. As of this writing, DAAPD was a masked package on Gentoo, so the actual command line I used to install it on my server PC was:
ACCEPT_KEYWORDS="~x86" sudo emerge -D -v daapd
The -D option gets the dependencies, and the -v is for increased verboseness (USE flags info, etc.). Then all I had to do was point the DAAPD server in the direction of my local tunes library on the Gentoo box, by editing /etc/daapd.conf and setting the Root parameter to be /path/to/my/choons. I also changed the ServerName variable. Then I started it up by typing /etc/init.d/daapd start>. I also used Gentoo's rc-update to ensure that the service would be started after a reboot as well:
/sbin/rc-update add daapd default
Next you have to announce your tunes library to your OS X boxes, which will discover them using Rendezvous (which is Apple's name for Zeroconf). The best way to do this is to use Porchdog's Howl. I won't go into the details of installing Howl, suffice to say on my Gentoo box, you just need a variant of emerge howl. Once Howl was installed, all I needed to do was edit /etc/conf.d/mDNSResponder and set the mDNS responder options to this:
MDNSRESPONDER_OPTS="-n `hostname` -t _daap._tcp. -p 3689"
This basically tells the mDNS responder to broadcast to the subnet that it has a DAAP service available on port 3689 (the standard port). Then I started Howl with /etc/init.d/mDNSResponder start. As with DAAPD, I used rc-update to add it to my boot-time startup:
/sbin/rc-update add mDNSResponder default
So, now that DAAPD was ready to serve tunes, and the DAAPD service was being announced via Howl (Rendezvous/Zeroconf), all I did was start iTunes on my Powerbook, and there was my tunes library. Sweet. This is what worked for me. I've only had it running a couple of days, but so far it is rock solid. I can't seem to add tunes to a playlist which is a bit annoying, but presumably an iTunes limitation. Good luck!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040409064130653