computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...

, the Inter-Client Communication Conventions Manual (ICCCM or I39L short for "I", 39 letters and "L")The X-Windows Disaster
Don Hopkins, UNIX-HATERS Handbook is a legacy standard protocol for the

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wit ...

. It specifies conventions for clients of a common X server about selections and cut buffers, communication with the

window manager A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment. They work in conjunction ...

and session manager, manipulation of shared resources, and color characterization. The

X Session Manager In the X Window System, an X session manager is a session management program, a program that can save and restore the current state of a set of running applications, including window manager. Overview From the point of view of an X session manag ...

Protocol (XSMP) is a successor to the ICCCM standard.

History

It was designed by

David S. H. Rosenthal David Stuart Holmes Rosenthal (born 1948 in Cambridge, United Kingdom) is a British-American computer scientist. Biography Rosenthal is the son of Michael David Holmes Rosenthal and Marjorie Mary "Molly" Rosenthal (both deceased). His brother M ...

of the

MIT X Consortium The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wit ...

from 1987 to 1989. A draft version appeared in March 1988 i
X11R2
This was removed fro
X11R3
Version 1.0 was released in July 1989 as part o
X11R4
Three window managers in the X11R4 contrib directory implemented support for ICCCM:
gwm

olwm olwm (OPEN LOOK Window Manager) was the default stacking window manager for OpenWindows, the original X11 desktop environment included with SunOS and Solaris. Its unique characteristic is its implementation of the OPEN LOOK look and feel. Sco ...

an
tekwm
Version 1.1 contains an update for color characterization and appeared i
X11R5
Version 2.0 has many changes in the areas of window management, selections,

session management In computer science and networking in particular, a session is a time-delimited two-way link, a practical (relatively high) layer in the tcp/ip protocol enabling interactive expression and information exchange between two or more communication de ...

, and resource sharing. It was released in May 1994 as part o
X11R6

Background

X deliberately specifies "mechanism, not policy" for how windows interact. As such, an additional specification beyond the X protocol itself was needed for client interoperation.

Features

The ICCCM specifies cut and paste buffers, window manager interaction, session management, how to manipulate shared resources and how to manage device colours. These low-level functions are generally implemented within

widget toolkit A widget toolkit, widget library, GUI toolkit, or UX library is a library or a collection of libraries containing a set of graphical control elements (called ''widgets'') used to construct the graphical user interface (GUI) of programs. Most widg ...

s or

desktop environment In computing, a desktop environment (DE) is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system that share a common graphical user interface (GUI), sometimes described as a graphica ...

s. This isolates application programmers from working directly with the ICCCM itself, as this functionality is delegated to the implementing toolkit.

Criticism

The ICCCM has received some criticism for being ambiguous and difficult to implement correctly. This was acknowledged in the preface of version 2.0, stating that it aimed "to fix problems with earlier drafts, and to improve readability and understandability". Furthermore, some parts may be obsolete or no longer practical to implement. The

Extended Window Manager Hints Extended Window Manager Hints, a.k.a. NetWM, is an X Window System standard for the communication between window managers and applications. It builds on the functionality of the Inter-Client Communication Conventions Manual (ICCCM). These standar ...

(EWMH) is a more recent standard, which, according to its introduction: "builds on the ICCCM, which defines window manager interactions at a lower level. The ICCCM does not provide ways to implement many features that modern desktop users expect." But it also states: "Clients which aim to fulfill this specification MUST adhere to the ICCCM on which this specification builds." insofar the EWMH doesn't overrule.

Freedesktop.org freedesktop.org (fd.o) is a project to work on interoperability and shared base technology for free-software desktop environments for the X Window System (X11) and Wayland on Linux and other Unix-like operating systems. It was founded by Hav ...

notes that "historically, X clients have not handled cut-and-paste in a consistent way" and formulates additional guidelines in
clipboards-spec

List of Window Managers that are ICCCM Compliant

* aewm — a stacking window manager. * alloywm — partial compliance. * awesome — a

dynamic window manager In computing, a dynamic window manager is a tiling window manager where windows are tiled based on preset layouts between which the user can switch. Layouts typically have a main area and a secondary area. The main area usually shows one window, b ...

that is configured in

Lua Lua or LUA may refer to: Science and technology * Lua (programming language) * Latvia University of Agriculture * Last universal ancestor, in evolution Ethnicity and language * Lua people, of Laos * Lawa people, of Thailand sometimes referred t ...

. *

Blackbox In Unix computing, Blackbox is a free and open-source stacking window manager for the X Window System. Blackbox has specific design goals, and some functionality is provided only through other applications. One example is the bbkeys hotkey a ...

Compiz Compiz () is a compositing window manager for the X Window System, using 3D graphics hardware to create fast compositing desktop effects for window management. Effects, such as a minimization animation or a cube workspace, are implemented as lo ...

dwm dwm is a minimalist dynamic window manager for the X Window System developed by Suckless that has influenced the development of several other X window managers, including xmonad and awesome. It is externally similar to wmii, but internally mu ...

— can be configured for compliance * enlightenment — also serves as a

Wayland compositor Wayland is a communication protocol that specifies the communication between a display server and its clients, as well as a C library implementation of that protocol. A display server using the Wayland protocol is called a '' Wayland composito ...

. * evilwm — partial compliance * EXWM (Emacs X Window Manager) — features ICCCM and EWMH compliance *

FVWM The F Virtual Window Manager is a virtual window manager for the X Window System. Originally a twm derivative, FVWM has evolved into a powerful and highly configurable environment for Unix-like systems. History In 1993, during his work analyzi ...

IceWM IceWM is a stacking window manager for the X Window System, originally written by Marko Maček. It was written from scratch in C++ and is released under the terms of the GNU Lesser General Public License. It is customizable, relatively lightw ...

KWin KWin is a window manager for the X Window System and a Wayland compositor. It is released as a part of KDE Plasma 5, for which it is the default window manager. KWin can also be used on its own or with other desktop environments. KWin can be c ...

— default window manager and Wayland compositor of KDE Plasma. *

Metacity Metacity was the default window manager used by the GNOME 2 desktop environment until it was replaced by Mutter in GNOME 3. It is still used by GNOME Flashback, a session for GNOME 3 that provides a similar user experience to the Gnome 2.x seri ...

— default window manager of

GNOME 2 GNOME 2 is the second major release of the GNOME desktop environment. Building upon the release of GNOME 1, development of GNOME 2 focused on a greater design-oriented approach that simplified and standardized elements of the environment. It als ...

. * musca * Openbox — the default window manager used by

LXDE LXDE (abbreviation for Lightweight X11 Desktop Environment) is a free desktop environment with comparatively low resource requirements. This makes it especially suitable for use on older or resource-constrained personal computers such as netb ...

and

LXQt LXQt is a free and open source lightweight desktop environment. It was formed from the merger of the LXDE and Razor-qt projects. Like its GTK predecessor LXDE, LXQt does not ship or develop its own window manager, instead LXQt lets the user ...

. *

vtwm Vtwm (the Virtual Tabbed Window Manager) is an X window manager that was developed from the twm codebase. The first release was in 1990, and it is very much an "old school" window manager, lacking desktop environment features. It added feature ...

* wmfs * xfwm *

xmonad xmonad is a dynamic window manager (tiling) for the X Window System, noted for being written in the functional programming language Haskell. Window manager Begun in March 2007, version 0.1 was announced in April 2007 as 500 lines of Haskell ...

References

External links

Inter-Client Communication Conventions Manual, Version 2.0

Inter-Client Communication Conventions Manual
Version 2.0 {{XWinSys Inter-process communication X Window System