Industrial applications use specific problem-oriented implementations of large sparse and irregular data structures. Hence there is a need for tools that make it possible for developers to visualize their applications in terms of these data, their structure, and the operations that are applied to them, whatever their effective implementation and their distribution are. In this paper, we present both a framework which we have setup to support the development of such tools, and prototypes which we have developed. The resulting environment is composed of two layers: the first layer is a model that we have defined and implemented as high level s that make it possible to efficiently abstract from the implementation; the second layer offers prototype tools built on top of these libraries. These tools are integrated within a graphical environment called Visit[7] which is part of the HPFIT research effort1 [7, 8, 9]. HPFIT is a joint project involving three research laboratories: LIP in Lyon,...