  This chapter discusses the institutional approach for organizing and
maintaining ontologies. The theory of institutions was named and initially
developed by Joseph Goguen and Rod Burstall. This theory, a metatheory based on
category theory, regards ontologies as logical theories or local logics. The
theory of institutions uses the category-theoretic ideas of fibrations and
indexed categories to develop logical theories. Institutions unite the lattice
approach of Formal Concept Analysis of Ganter and Wille with the distributed
logic of Information Flow of Barwise and Seligman. The institutional approach
incorporates locally the lattice of theories idea of Sowa from the theory of
knowledge representation. The Information Flow Framework, which was initiated
within the IEEE Standard Upper Ontology project, uses the institutional
approach in its applied aspect for the comparison, semantic integration and
maintenance of ontologies. This chapter explains the central ideas of the
institutional approach to ontologies in a careful and detailed manner.
