Remote File Sharing
Remote File Sharing (RFS) was a distributed file system developed by AT&T in the 1980s. It was first delivered with UNIX System V Release 3 (SVR3). It was also included in AT&T's UNIX System V Release 4, but as that also included NFS which was more interoperable, RFS was little used. Some licencees of AT&T's UNIX System V Release 4 didn't include the RFS support in their SVR4 distributions, and Sun Microsystems removed it from Solaris 2.4.