On 2005-11-21 new icons by AndrewZhilin were added to Emacs. These icons use the letters E and M stylized as the horns of a gnu. The dark blue icons come in 16 and 24 pixel sizes and there is are alternatives sized 32 and 48 pixel looking like spiral-bound (paper) notebooks.

They are expected to be used by operating system distributors who combine GNU Emacs in conjuction with desktop systems like Gnome. The icons are mentioned in the FOR-RELEASE file in Emacs’s source distribution for the very purpose of noting Emacs package maintainers.

https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/16x16/apps/emacs22.pngA small 16 by 16 pixel Emacs icon.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/24x24/apps/emacs22.pngA larger 24 by 24 pixel Emacs icon.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/32x32/apps/emacs22.pngA 32 by 32 pixel Emacs icon appearing on a slanted notebook.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/48x48/apps/emacs22.pngA larger 48 by 48 pixel Emacs icon appearing on a slanted notebook.

Emacs 23 will use OSX style icons by KentaroOhkouchi:

https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/16x16/apps/emacs.pngA small 16 by 16 pixel Emacs icon.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/24x24/apps/emacs.pngA larger 24 by 24 pixel Emacs icon.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/32x32/apps/emacs.pngA 32 by 32 pixel Emacs icon with a pen.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/48x48/apps/emacs.pngA larger 48 by 48 pixel Emacs icon with a pen.
https://cvs.savannah.gnu.org/viewvc/*checkout*/emacs/emacs/etc/images/icons/hicolor/128x128/apps/emacs.pngA large 128 by 128 pixel Emacs icon with a pen.
SVG fileA scalable version of the Emacs icon, by ChongYidong.

See also EmacsLogo, EmacsPowered, EmacsWallpaper.

Other Emacs Icons

Traditional overflowing kitchen sink; see the Emacs Jargon File entryKitchenSinkBW KitchenSinkWhite
Long-time icons for EmacsForWindows by Rob Davenport, the 16x16 variant visible in the taskbar was hard to recognize GnuHeadDavenport
Proposed icon suggested by Norman Walsh (“That’s not my design on that page. I don’t have that much artistic talent. I found it on the web somewhere.”)GnuHeadWalsh
CarbonEmacs uses the colored gnu head by Joseph W. ReissGnuHeadReiss
CarbonEmacsPackage uses the OSX-style variant by K. Ohkouchi CarbonEmacsPackageIcon
AquamacsEmacs uses the gnu head by Massimiliano GubinelliGnuHeadGubinelli
Gentoo used to have several round versions of the gnu head.https://sources.gentoo.org/viewcvs.py/*checkout*/gentoo/xml/images/icons/l33t_TXT_emacs.png https://sources.gentoo.org/viewcvs.py/*checkout*/gentoo/xml/images/icons/l33t_TXT_emacs2.png https://sources.gentoo.org/viewcvs.py/*checkout*/gentoo/xml/images/icons/l33t_CLR_emacs.png https://sources.gentoo.org/viewcvs.py/*checkout*/gentoo/xml/images/icons/l33t_PUR_emacs.png
MilesBader made some very shiny raytraced icons in a vaguely OSX style (see the linked-to page for various sizes, up to 1920x1920)https://download.savannah.gnu.org/releases/emacs/icons/emacs5-128.png https://download.savannah.gnu.org/releases/emacs/icons/emacs6-128.png
Emacs is Sexy has some alternative Icons.