NSPR provides platform independence for non-GUI operating system
facilities.
These facilities include threads, thread synchronization, normal file
and network I/O, interval timing and calendar time, basic memory
management (malloc and free) and shared library linking.
A good portion of the library's purpose, and perhaps the primary purpose
in the Gromit environment, is to provide the underpinnings of the Java
VM, more or less mapping the sys layer that Sun defines for the porting
of the Java VM to various platforms.  NSPR does go beyond that
requirement in some areas and since it is also the platform independent
layer for most of the servers produced by Netscape
