["display manager"] >


["X"] supplies ["XDM"] as the standard basic display manager.

XDM (the X Window Display Manager) originated in ?X11R3. This version suffered from several problems, most notably 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

XDM is incompatible with ["GDM"] (one cannot login). It you have XDM runing and type

another ["X"] screen is opened (i.e. Screen 1 for xdm, instead of Screen 0, that is used for xdm). You can solve definitively this problem uninstaling xdm.