Icon libraries are special DLL (Windows dynamically linked library) files which may contain embedded icons and cursors called resources. These icon libraries have the extension ICL and are mainly used for distributing a huge collection of icons over the Internet.
The properties of a resource are:
Icon or cursor. Although there are many other types of resources (string, dialog, font, etc.), ICL files rarely have these types of resources and GFIE does not support editing them.
An identifier which consists of uppercase letters, numbers and underscores.
Stored as an integral number, this property has little importance at icon and cursor resources. Mainly used for dialog and string resources.
Saving resource compilations in Win32 .RES file format is also supported. This makes GFIE a specialized resource editor. (Opening and saving a .RES file should also keep the other resources like strings or dialogs - which are hidden in GFIE's library editor window -, but creating a backup of your original file is recommended.)