Fontconfig grew out of the need to configure fonts for use with the X render extension, first as a part of the Xft library and then as a completely separate library ready for use by any application needing to locate and select fonts. It is designed to provide many options for application development so that applications can use the parts of the library that match their requirements and avoid those that do not.
It is to be hope that this library will engender some commonality in the configuration, customization and use of fonts within the desktop environment and beyond.