An object library is a file that contains a group of one or more compiled ACUCOBOL-GT programs and its associated resource files (such as bitmaps and WAV files). Object libraries can simplify the distribution of an application by reducing the number of files involved. They can also help improve performance by reducing the number of directory operations performed by runcbl when it is loading object modules.
When you create an object library, the first module (compiled object) that you specify is called the primary module. When the library is loaded via a CALL statement or because it is the first program of the run unit, the primary module is the program that is loaded and run. Other modules in the library can be loaded by subsequent CALL statements.
You should keep several things in mind when you work with the cblutil object library utility: