GQview is an easy-to-use and lightweight image viewer for X11 (*nix). It is based on the GTK+ toolkit but does not use any GNOME (GNU Network Object Model Environment) libraries. It supports all of the graphics formats recognised by the gdk-pixbuf library, including JPEG, PNG, GIF, TIFF, and BMP.
The GQview interface is very simple. A list of directories, a list of image files in the current directory, and a large pane for displaying the current image. Everything is based on single clicks. The one feature of GQview that I miss in other image viewers is that a left-click on the image switches to the next image and a middle-click switches to a previous image. This allows quick scanning through the images in a directory to find the one you're looking for. There is also support for thumbnails.
Additional features of GQview allow it to also be used to manage image files. Copying, moving, renaming, and deletion are all available from the main interface. Surprisingly (for a *nix app), it has an option to set the desktop background. I am not sure if this works under KDE, but it should under GNOME and does under WindowMaker.
GQview is released under the GNU GPL and can be found at http://gqview.sourceforge.net
This writeup is copyright 2002 D.G. Roberge and is released under the Creative Commons Attribution-NonCommercial-ShareAlike licence. Details can be found at http://creativecommons.org/licenses/by-nc-sa/2.0/ .