Windows 9x:
XnView can display icons which are contained in icon libraries (*.ICL) and the files of the types *.DLL, *.EXE, *.OCX and *.CPL. The icon libraries are handled like multi page images. To display you open the respective file as normal. XnView opens the icon library and displays the first image. You change between the frames of the icon library or file with the buttons of Previous Frame/Next Frame.
Please note that in the status bar, the file size displayed is for the complete file, and not that of the currently displayed frame.