Windows 2000 shares the same underlying networking protocol as UNIX systems, making coexistence and even full interoperability possible. SFU provides all the tools to share file system resources with UNIX hosts, either as a server or as a client, and third-party SMB tools also provide this functionality from the UNIX side. Adding Services for UNIX to Windows 2000 provides not only a familiar environment for UNIX users and administrators, but also a full-featured, robust, and resource-sparing environment to run UNIX programs natively, and the built-in Windows 2000 Telnet client and server lets users from either system log on to the other. The next chapter extends the interoperability story to cover Apple Macintosh computers.