SSODS provides the minimal software environment required to run Squeezebox Server (SS), the software required to play music on the Squeezebox family of streaming audio players (see http://www.logitechsqueezebox.com).
SSODS used to stand for SlimServer on DiskStation. When Slimserver had been renamed to SqueezeCenter the abbreviation did not work anymore but was kept never the less. Now we have Squeezebox Server and the abbreviation fits again. Hence, today SSODS is Squeezebox Server on DiskStation.
However, SSODS has evolved and is not limited for use on a DiskStation. SSODS is built in a way that enables it to run independently from the system installed on a particular machine. And it should not interfere with other programs that are installed on the machine either. All SSODS needs is a Linux 2.6 kernel and a means to start it (e.g. via init(1) or an system boot (rc) script). SSODS is available for several platforms. Many NAS devices (Diskstations, Turbostations, and others) should be able to run it. For some systems, installable packages are available through the SSODS website or from third parties (e.g. NAS manufacturers).
Should you consider installing SSODS be sure to read and consider the warnings.