Design patterns and Fortran 90/95

In the literature on object oriented programming (OO), design patterns are a very popular subject. Apart from any hype that may be connected to the concept, they are supposed to help you look at a programming problem and come up with a robust design for its solution. The reason design patterns work is not that they are something new, but instead that they are time-honoured, well-developed solutions.I will not repeat the story about architectural design patterns and Christopher Alexander who recognised their potential. Instead I will try to explain how these (software) design patterns can be used in setting up Fortran 90/95 programs, despite the "fact" that Fortran 90/95 lacks certain OO features, such as inheritance and polymorphism. It may not be stressed in all OO literature, but design patterns help you find solutions that do not necessarily involve inheritance or polymorphism (cf. Shalloway and Trott, 2002).Design patterns come by fancy names such as the Adapter pattern or the Decorations pattern and explaining what they are and how to use them is best done via a few examples.