we develop an approach for reconciling open programming -- the development of programs that support dynamic exchange of higher-order values with strong static typing. conventional functional language extended with a set of orthogonal features like higher-order modules, dynamic type checking, higher-order serialisation, and concurrency. On top of these a flexible system of dynamic components and a simple but expressive notion of distribution is realised. The central concept in this design is the packag}, a first-class value embedding a module along with its interface type. formal model for abstract types that is not invalidated by the presence of primitives for dynamic type inspection, as is the case for the standard model based on existential quantification. For that we present an idealised language in form of an extended lambda-calculus, which can express dynamic generation of types.