The sppc library is a collection of very low level functions, that have kernel specific implementations. It forms the building blocks for the S++ standard library, which includes sppc via the ffi system. As S++ evolves, more system calls will be required, which this library will provide.

Other "low level" functions not exposed from this library are exposed using llvm, which generates assembly code directly, such as the math sin, cos, etc. functions. Implementing the sppc functions in assembly would be extremely difficult becausebthey would need to use direct system calls, which change constantly, and would need to target multiple processors and operating systems. Using C allows for this to be abstracted over.