NFS is often used with Unix operating systems (such as Solaris, AIX, HP-UX), Apple's macOS, and Unix-like operating systems (such as Linux and FreeBSD). It is also available to operating systems such as Acorn RISC OS,[14] AmigaOS, the classic Mac OS, OpenVMS,[3] MS-DOS,[15] Microsoft Windows,[16] OS/2,[17] ArcaOS,[18] Novell NetWare,[19] and IBM AS/400.[20] Alternative remote file access protocols include the Server Message Block (SMB, also termed CIFS), Apple Filing Protocol (AFP), NetWare Core Protocol (NCP), and OS/400 File Server file system (QFileSvr.400).