If you are using an Apple device (ie, I have an ipod), AFAIK it is not completely possible avoid itunes, because you will always need apple services running in the background, but this is the way I am using it with foobar, I can synch my ipod with my pc, and do everything I did previously with itunes.
You will have to download itunes, I downloaded an old version because it seems to me that apple add new crap every new release of this program, I downloaded itunes 10 x64 from here:
http://www.oldapps.com/itunes.php
Once downloaded your itunes setup you have to unpack it using 7-zip in a folder of your choice. Once unpacked you will see these files: QuickTime, this is the Apple's multimedia application, I am pretty sure you already know it. There is a lighter variant called QuickTime Alternative. iTunes (iTunes64 for x64 OS) is the media player. It is needed to sync portabled Apple's devices with your computer. Also this allow accessing iTunes Store, but I never used it. Apple Application Support Added since iTunes 9 this manage iPhone applications, iPod Touch and iPad. It is required both for QuickTime and iTunes. If missed you most probably will have an error message. Bonjour (or Bonjour64) this is crap, they say it is used to discover local network services. It is installed by default with itunes but I find it useless. You probably would need it if you use Apple TV, Airport, Airplay and whichever wireless share. If you use any of these and you don't install Bonjour most probably you will have an error message that, once ignored, will not appear again. Apple Mobile Device Support (or AppleMobileDeviceSupport64) it is used to sync iPhone, iPod Touch e iPad. You don't need it if you use iPod Classic, Mini, Nano, or Shuffle, these can be used with standard application. Apple Software Update this is used to search new software versions. SetupAdmin this is the installer, you don't need it.
once unpacked I created a .bat file (for my convenience, you can just throw commands once at time if you prefer), and executed this:
AppleApplicationSupport.msi /passive
QuickTime.msi /passive
iTunes.msi /passive
AppleMobileDeviceSupport64.msi /passive
I guess order is not important, but I followed the previous one. The last command (AppleMobileDeviceSupport64.msi) is required if you want to sync an iphone or ipod touch (as I have, so I included it).
For foobar, I used this component:
https://yuo.be/ipod_manager
After you have Foobar2000 setup, and downloaded the iPod Manager component (link above) (The current version supports with iOS 4 on your iPod Touch but not the iPhone 4), unzip foo_dop.dll to C:\Program Files\Foobar2000\Components. Read carefully the compatibility list in the foobar's plugin before do everything, here it is working, but I really can't say if it can work for anybody else.
Hope this is of some help.