• A conforming Origami publication remains an ordinary readable EPUB when advanced features are unavailable. • Richer functionality does not require the reader to surrender access to a proprietary document container. • Important document structure and metadata can remain available even if the original publisher, server, or software vendor disappears. • A reader can benefit from precise citations, definitions, accessibility structure, and trustworthy provenance without needing to understand the underlying metadata model. • Web-based and ordinary EPUB reading remain possible alongside richer native or spatial experiences.