EPUBFormate

EPUBFormate is a proposed open specification for electronic publications that is intended as an extension of the EPUB format. It aims to modernize packaging, metadata, and multimedia capabilities while preserving the core EPUB principle of reflowable text, making it possible to deliver richer content without abandoning established EPUB workflows.

The concept behind EPUBFormate arose from community discussions and experimental proposals to address evolving reader expectations, such as enhanced interactivity and accessible design. It is not an official standard published by major standards bodies, and as such, support varies across reader applications and authoring tools.

Technical overview and features include preserving the ZIP-based container structure common to EPUB, with a dedicated mimetype and a content directory, while extending the manifest, spine, and metadata to accommodate richer resource types. Key innovations often described for EPUBFormate include improved support for multimedia (video and audio alongside HTML5), interactive components, richer accessibility metadata, and more flexible layout and typography options. It also envisions a more explicit mechanism for extensible media types, scripting within a sandbox, and enhanced internationalization support, all designed to coexist with standard EPUB content.

Adoption and tooling remain limited compared to established EPUB workflows. Because EPUBFormate is not widely standardized, authors who experiment with it typically provide fallback options in standard EPUB form to maximize reader compatibility. In practical use, publishers should evaluate reader support and toolchain readiness before adopting EPUBFormate for production workflows.

See also: EPUB, EPUB 3, digital publishing, accessibility.