Numerical analysis of thermo-hydro-mechanical coupled finite element problems in fractured or porous media involves significant computational resources and parallel computing is a way to enable the use of the necessary computer power of SMP machines or clusters. An interdisciplinary collaboration is essential to port large scale and complex software applications efficiently to parallel platforms with shared or distributed memory. A comprehensive and continuously developed scientific software concept is required to treat the aspects of parallelization. We describe a resourceful and practicable software environment that enables the execution of serial or parallel applications, and which makes a transparent administration of the source code for a scientific group possible. Such software environments are difficult to design and implement, especially when solution adaptive techniques are used and three-dimensional problems on complex geometries are faced, which yield the use of unstructured meshes. In this paper, we present object-oriented software concepts and parallelization methods for serial/parallel runs and coupled/non-coupled schemes on single or multiple processes. Applications of different numerical simulations on different parallel computer platforms are described and compared to demonstrate the computational efficiency of the developed structures and procedures.