An open-source initiative taking ePub development to the next level.

Explore the opinionated, standard-based introduction of ePub implementation specifications to learn more about the project.

Explore the guidelines that include deliverables, file structure, validation, revisions, packaging, and all the essential details needed before involving in the project.

See the information covering the container and encryption.xml.

Read all the details regarding OPF files, Firebrand, OPF Manifest, OPF Metadata, and OPF Spine.

Learn all the information you need regarding CSS Validation, CSS Shorthand, and CSS Overrides, and explore relevant tutorials.

Check out all the fonts guidelines, best practices, and font errors.

Rules regarding cover images, full-page images, full-width images, floating images, and more.

Explore all the XHTML general information and specific rules, from XHTML heads, ePub types, and page breaks to drop caps and contents.

Dive into the rules for building the table of contents.