The x3270 program opens a window in the X Window System which emulates
the actual look of an IBM 3278/3279 terminal, commonly used with
mainframe applications. x3270 also allows you to telnet to an IBM
host from the x3270 window.
Install the x3270-x11 package if you need to access IBM hosts using an IBM
3278/3279 terminal emulator from X11.