30.6 Summary

The first two applications that we covered, Finger and Whois, are for obtaining information on users. Finger clients query a server, often to find someone's login name (for sending them mail) or to see if someone is currently logged in. The Whois client normally contacts the server run by the InterNIC, looking for information on a person, institution, domain, or network number.

The other Internet resource discovery services that we briefly described, Archie, WAIS, Gopher, Veronica, and WWW, help us locate files and documents across the Internet. Other resource discovery tools are currently being developed.

This chapter finished with a brief look at the X Window System, another heavy user of TCP/IP. We saw that the X server manages multiple windows on a display, and handles the communication between a client and its window. Each client has its own TCP connection to the server and a single server manages all the clients for a given display. With the Xscope program we saw how it's possible to place another program between a client and server to output information about the messages exchanged between the two.