This thesis describes the design and the implementation of an Ada library for positional board games. The library consists of general software modules that use some concepts from a model of Positional Board Games presented in [Antoy 87]. This thesis shows that general software modules based on the mathematical concept of board can be built and used by any positional board game program. Furthermore, this thesis describes the data types used in the modules and presents informal and formal specifications of the operations on the data types. It also describes the implementation of the data types; presents the algorithms implementing the operations and shows how the library can be used on two positional board programs and justifies the claim of generality and simplicity of the model in [Antoy 87]. The programming language Ada is used to express the formal specifications and to code the software modules. / Master of Science