1. Serial Line Internet ProtOcol. 2. Symmetric LIst PrOcesssor. Early 1960' s list prOcessing subroutine package for Fortran by J. Weizenbaum. Later also embedded in MAD and ALGOL. ["Symmetric List PrOcessor", J. Weizenbaum CACM 6:524-544(1963). Sammet 1969, p.387].