To achieve sharing and reuse for sustainable development, documents are semantically interrelated by ontologies, specified formally using the specification language Casl. The specification of properties for relations in the system’s ontology is used to check invariant properties during change management. Documents are structured for fine-grained management of variants for essentially the “same” concept in various representations. This technology is self-applied to the “literate” development of consistent (interrelated packages of) documented ontologies.