Introduction to the Module

Abstract

The Fortran 90 module provides the language with a flexible new category of program unit. In its simplest usage, the module is a vehicle for packaging collections of data specifications and/or sharing data between separately compiled program units. But in addition to data specifications, modules may also contain subprograms, providing capabilities somewhat similar to the package in Ada and the class in C++. The Fortran 90 module can be used to segment large, unwieldy programs into smaller, more manageable pieces, and it can be employed to package the source code for intimately related data and procedures in the same program unit, which promotes software maintainability and reusability.