iDesk gives users of minimal wm's (fluxbox, blackbox, openbox, windowmaker...) icons on their desktop. The icon graphics are either from a png or svg (vector) file and support some eyecandy effects like transparency. Each icon can be confgured to run one or more shell commands and the actions which run those commands are completely configurable. In a nutshell if you want icons on your desktop and you don't have or dont't want KDE or gnome doing it, you can use idesk (source: ?idesk website).
Use PNG images for icons, which generally stored in /usr/share/pixmaps (i.e. /usr/share/pixmaps/mozilla.png for Mozilla).
idesktool is a point'n'click configuration tool for idesk to make new icons, modify existing ones, delete them or refresh the desktop. It will also simplify setting up idesk by writing an ideskrc file and making the idesktop folder for you. While it was designed to be used with the idesk-extras package - and I highly recommend idesk-extras as the easiest way to get idesk running - it will work without it too
This is the file where the idesk icons are stored. A default.lnk example (that executex mozilla browser):
table Icon Caption: Mozilla Browser Command: mozilla Icon: /usr/share/pixmaps/mozilla.png X: 43 Y: 197 end
New option Background.File for background image (wallpaper) in .ideskrc file example Background.File: /path_to_image/background.jpg