This is 1.5 of the Extended Window Manager Hints (EWMH) spec, updated 2013-01-25. The canonical home for this document is http://www.freedesktop.org (http://www.freedesktop.org/standards/wm-spec/), which also contains directions for reporting bugs or contributing to future versions.

This spec defines interactions between window managers, compositing managers, applications, and the utilities that form part of a desktop environment. It builds on the Inter-Client Communication Conventions Manual [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. The GNOME and KDE desktop projects originally developed their own extensions to the ICCCM to support these features; this spec replaces those custom extensions with a standardized set of ICCCM additions that any desktop environment can adopt.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

The key words "Window Manager" refer to a window manager which is adopting this specification. "Pager" refers to desktop utility applications, including pagers and taskbars. "Application" refers to other clients. "Clients" refers to Pagers and Applications ie. all X clients, except for the Window Manager.

Window Managers and Clients which aim to fulfill this specification MUST adhere to the ICCCM on which this specification builds. If this specification explicitly modifies the ICCCM Window Managers and Clients MUST fulfill these modifications.