A computer program product has program code adapted to provide, upon execution, a database of objects and a database engine for managing the objects. Each object comprises metadata for describing the object and for defining a hierarchical structure of branches which constitutes the object and which includes relations to other objects. An individual branch has a metadata type, which is selected from a predetermined and limited set of n different metadata types and which represents one respective hierarchical level in the hierarchical structure, and a metadata value. An individual branch may also have an arbitrary number of other branches, of any hierarchical level strictly subordinate to the hierarchical level of the individual branch, connected to the individual branch as children thereof. The arbitrary number may include zero branches.