A Configuration File is a text file that can be examined (and modified, in the case of user-modifiable configuration file) with any text editor. The extension of a configuration file is .cfg.

OpenCities Map's configuration file processing can be regarded as interpreting a simple program, part of which is provided by system configuration files, which should not be modified by the user, and part of which is provided by configuration files that are intended to be user modified.

The system configuration files are located in the ..\config folder of OpenCities Map's program directory, while user-modifiable configuration files are in the ..\Configuration directory or other user-specified directories. User-modifiable configuration files are included into the configuration file processing flow at appropriate times by the system configuration files.

While running OpenCities Map, you can see the current values of all Configuration Variables using the SHOW CONFIGURATION key-in. This key-in produces a text file which is also opened in Notepad (default editor) showing the current value of all Configuration Variables.