History
XDM (the X Window Display Manager) originated in X11R3. This first version, written by Keith Packard of the MIT X Consortium, had several limitations, the most notable of which was that it could not detect when users switched X terminals off and on. In X11R3, XDM only knew about an X terminal from its entry in the Xservers file, but XDM only consulted this file when it started. Thus every time a user switched a terminal off and on, the system administrator had to send a SIGHUP signal to XDM to instruct it to rescan Xservers.
XDMCP arrived with the introduction of X11R4 (December 1989). With XDMCP, the X server must actively request a display manager connection from the host. An X server using XDMCP therefore no longer requires an entry in Xservers.
Read more about this topic: X Display Manager (program Type)
Famous quotes containing the word history:
“To history therefore I must refer for answer, in which it would be an unhappy passage indeed, which should shew by what fatal indulgence of subordinate views and passions, a contest for an atom had defeated well founded prospects of giving liberty to half the globe.”
—Thomas Jefferson (1743–1826)
“Postmodernism is, almost by definition, a transitional cusp of social, cultural, economic and ideological history when modernism’s high-minded principles and preoccupations have ceased to function, but before they have been replaced with a totally new system of values. It represents a moment of suspension before the batteries are recharged for the new millennium, an acknowledgment that preceding the future is a strange and hybrid interregnum that might be called the last gasp of the past.”
—Gilbert Adair, British author, critic. Sunday Times: Books (London, April 21, 1991)
“In nature, all is useful, all is beautiful. It is therefore beautiful, because it is alive, moving, reproductive; it is therefore useful, because it is symmetrical and fair. Beauty will not come at the call of a legislature, nor will it repeat in England or America its history in Greece. It will come, as always, unannounced, and spring up between the feet of brave and earnest men.”
—Ralph Waldo Emerson (1803–1882)