Twm

Infobox Software
name = twm



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author = Tom LaStrange
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released = 1987
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programming language = C
operating system = Unix-like
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genre = Window manager
license = MIT License
website = In computing, twm (Timeless Windows Manager) is the standard window manager for the X Window System, version X11R4 onwards. twm was created by Tom LaStrange. It is a re-parenting window manager that provides title bars, shaped windows and icon management, and is extensively configurable.

twm was a breakthrough achievement in its time, but has been largely superseded by other window managers and is no longer maintained. Despite being obsolete, it made a strong impact on the development of X window managers. Many others, such as vtwm, tvtwm (also by LaStrange), CTWM, FVWM and their derivatives, were built on its code, while many others used concepts pioneered by it.

Although it is now generally regarded as the window manager of last resort, a small but dedicated minority of users favor twm for its simplicity, customizability, and light weight — partly due to being written in C directly against Xlib rather than based on a widget toolkit. twm is still standard with the X.Org reference implementation and is available as part of many X distributions. The Knoppix live CD will resort to twm if the computer it is running on lacks the RAM for a more sophisticated window manager.

Using twm

twm's interface is very different from that of common X window managers and desktop environments of the present day, which tend to work similarly to the Apple Macintosh or the various versions of Microsoft Windows. New users often find twm difficult to understand without reading the manual page.

In the default configuration of twm, the title bar has two buttons:
*"Resize button" (nested squares): the user clicks here, drags the mouse pointer to the edge they wish to move, then releases when the window is the desired size.
*"Iconify button" (circle): reduces the window to an icon.

There is no title bar button to close a window. A left click on the desktop brings up a menu, which includes an option to kill a window.

A "left click" on the title bar brings the window to the top of the window stack; a "middle click" moves the window; a "right click" sends the window to the bottom of the window stack.

Window focus follows the mouse pointer (point-to-focus), rather than being on whichever window was clicked last (click-to-focus).

When a new window is created, a 3×3 grid is displayed following the mouse pointer, waiting for the user to click where they wish the window to appear — left-click to appear in that position with that size, middle-click to resize the window before its creation, right-click to appear at that position but long enough vertically to reach the bottom of the screen.

Note that any of the above may be changed with appropriate changes to the configuration file.

History

twm was written by Tom LaStrange, then at Evans and Sutherland, starting in 1987, owing to frustration with the then-standard uwm: "I sat down at my monochrome Sun 3/50 and typed vi twm.c and then opened the X11 documentation. twm was my first X program. About six months later, I convinced my manager to let me send a copy to the comp.windows.x newsgroup." [http://www.linuxplanet.com/linuxplanet/reports/3000/2/] A version for X11R1 was published on the Usenet newsgroup comp.unix.sources on June 13, 1988.

Nine months later, Jim Fulton of the MIT X Consortium approached Tom and asked that he turn over the maintenance of the code to the X Consortium. Fulton made it compliant with the then-new Inter-Client Communication Conventions Manual and Keith Packard added support for shaped title bars. Subsequently, twm was released as the standard sample window manager for X11R4, replacing uwm.

twm originally stood for Tom's Window Manager. When the X Consortium took over its maintenance, and several other people had contributed substantially, its name was changed to Tab Window Manager. The vtwm.gamma man page says:

:To save Tom LaStrange from being blamed for any of the massive numbers of changes that have been done to twm since he gave up control of it, the name "twm" now stands for "Tab Window Manager".

According to Fulton, the word "tab" was picked because it conveniently started with T and put the emphasis on the squeezing feature window title bars, which made them look like folders with tabs.

Authors

twm was originally written by Tom LaStrange. Later substantial contributors include Jim Fulton, Keith Packard and Dave Sternlicht, all three at the X Consortium at the time, Steve Pitschke, then at Stardent Computer, and Dave Payne, then at Apple Computer.

References

* [http://xorg.freedesktop.org/X11R6.8.2/doc/twm.1.html twm — Tab Window Manager for the X Window System] — man page (X.org)
* [http://xwinman.org/vtwm.html Tab Window Manager] (xwinman)
* [ftp://ftp.isc.org/usenet/comp.sources.unix/volume15/twm/ Original comp.unix.sources posting]
* [http://www.lastrange.com/work/twm.pdf An Overview of twm (Tom's Window Manager)] (PDF) — Tom LaStrange, Xhibition '89 Conference Proceedings — concerning pre-ICCCM versions of twm
* [http://www.linuxplanet.com/linuxplanet/reports/3000/2/ From the Desktop: Tom LaStrange Speaks!: Talking with a Man Named Tom] (Brian Proffitt, "LinuxPlanet", Tuesday 6 February 2001)