An executable computer program is dynamically constructed by tightly coupling a plurality of dynamically loadable modules. Each modules includes a fully encapsulated function which is typically called from another module. A registration system is employed to associate a pointer with each defined function. In the modules, at run time, each function call is resolved using the associated pointer from the registration system. In particular, each function call is dereferenced by the associated pointer. Consequently, the resulting executable computer program is both flexible and efficient.