I run a Linux mt-daapd server, serving up my music library over the network to iTunes clients. It works well, and I love it, but it's always really annoyed me that if I had an intel-based PC as an audio streaming client, I needed to run Windows so I could run iTunes.
I've been looking at this periodically for a while, as it makes perfect sense to me that an old PC/laptop could be used as a music streaming client, but I'd rather not run Windows and spend my life worrying about anti-virus, spam, malware and all that great stuff that comes along with it. Basically, I'd rather run Linux.
Previously I'd looked at TunesBrowser (painful install, never got it to work, doesn't seem to be updated that often), One2OhMyGod (Java, runs on anything, but a bit basic), and even iTunes itself under WINE (older versions only, breaks with new iTunes releases).
Luckily, I have now found Banshee, which is the answer I have gone for. It's in the repositories for Ubuntu Dapper (Universe, I think) which makes installation a snap and is how I'm running it, but many other distros are also supported.
Update: The version of Banshee in the official Ubuntu repository is somewhat outdated, it seems. After having a few problems with searching my network library (Banshee hangs) and general performance issues (hogging CPU), I found badgerports via an outdated page at the Banshee site. Using badgerports, all my mono stuff and Banshee are brought bang up to date, and things appear to be improved.... :)
Note, however, that a little command-line usage goes a long way with badgerports - do an apt-get dist-upgrade after updating the repositories as instructed to get all the goodness.
Update 2: Although Banshee was improved, I still had some issues with shared libraries, so I decided to copy a subset of my library to the local machine. When played from a local source, I got intermittent breaks in the audio. I don't know if this is just that the machine is sub-par for all the mono-ness (PIII700 laptop, 256MB) or what, but it was getting frustrating.
Next step was to try the default Rhythmbox player shipped with Ubuntu to play the local tunes, and hopefully avoid the problems. Guess what? - it works great, and also to my surprise, shows my daap-shared library in the source pane.
Now, I have checked this, and Rhythmbox does not find shared libraries by default in Ubuntu, so some of the stuff I installed to support Banshee has made this happen, but unfortunately, I don't know which bits..... still, I have a smooth, fully working music player with shared library support on the old laptop, and that music player is Rhythmbox.
Update 3: I have recently deployed an Ubuntu 6.10 (edgy) system, and achieved the goal of playing iTunes shared libraries from Rhythmbox without all the Banshee/Mono crap as follows:
apt-get install gstreamer0.10-ffmpeg gstreamer0.10-plugins-bad gstreamer0.10-plugins-ugly gstreamer0.10-plugins-bad-multiverse gstreamer0.10-plugins-ugly-multiverse gstreamer0.8-plugins
Then edit /etc/default/avahi-daemon so that
AVAHI_DAEMON_START=1
Restart avahi-daemon (or reboot), and Rhythmbox now discovers and plays all your local iTunes shared libraries.
:)