Xpenology is an incredible project allowing to turn an old computer into a « Synology » NAS in order to test it. I say « test » because the legality around the project is unclear: while synology publishes its source code (http://sourceforge.net/projects/dsgpl/), not everything is considered as « open », and officials at Synology considers that it goes against their copyright… (see, in French).
I currently test it on an old netbook, and beside the obvious disk space limitation (one small hard drive on it), it works perfectly.
One aspect that I struggled to get right was to be able to play music locally, through an USB sound card connected to the netbook. There used to be a whole list of user reported compatible USB devices, but sadly it is now down and can only be accessed through archive.org.
Based on that list, I tried first with a Creative X-Fi Go, and then a Creative X-Fi HD, but to my dismay it was not working at all. The « official » (from Synology) documentation is rather poor, they just tell you to plug the device, and then it should be magically appearing in « Audio Station ».
To achieve this wizardry, you need to modify the following settings (i.e. grant to your user the rights for « USB/DLNA renderer »):
Quite simple isn’t it? Well it took me a few months of random attempts to find out…
It currently play with the Creative X-Fi HD, I will report later on the other devices that I may test.