We present an overview of the formalisation of parameterised specifications in the abstract framework of institution theory. Our aim is to establish those properties of specification languages with a primary function in building parameterised specifications and in supporting the instantiation of the parameters such that the resulting specifications satisfy expected algebraic properties. The abstract developments are illustrated through a series of concrete specifications over many-sorted algebra or its refinements obtained by taking into account an order relation on the sorts or a distinguished set of partial operations. We consider both simultaneous and sequential instantiation of parameters, and allow not only sharing between the body of the parameterised specification and the instances of the parameters, but also between the various parameters of a generic specification. The examination of the isomorphism relation between the results of the simultaneous and the sequential instantiation of parameters concludes our work. |