During the past few years, the productivity has been considered as one of the most important aims in developing softwares. Many practitioners and theorists are trying reuse ready made codes to increase the productivity of software development and the quality of their products. This paper introduces our experiences in developing a highly reusable class library and its reusing environment for building a database interface application. And the concepts, Structured Multi-Library and Dual Views of Class Inheritance, are also suggested, which consist our main conceptual framework in our work. Details in implementation are discussed in brief at the end.