xterm

Normally focus switches between X applications as the user moves the pointer (e.g., a mouse cursor) about the screen, but xterm provides options to grab focus (the Secure Keyboard feature) as well as accept input events sent without using the keyboard (the Allow SendEvents feature).

It was originally written as a stand-alone terminal emulator for the VAXStation 100 (VS100) by Mark Vandevoorde, a student of Jim Gettys, in the summer of 1984, when work on X started.

As Gettys tells the story, "part of why xterm's internals are so horrifying is that it was originally intended that a single process be able to drive multiple VS100 displays.

"[5] After many years as part of the X reference implementation, around 1996 the main line of development then shifted to XFree86 (which itself forked from X11R6.3), and it is now maintained by Thomas Dickey.

To access xterm's three menus, users hold the control key and press the left, middle, or right mouse button.

Example showing xterm's toolbar.
Chart of the 256 colors available in an xterm with color support. XTerm color numbers and RGB values are shown for each. (Updated 2024)