EPUB

An open standard file format for digital books and publications maintained by the World Wide Web Consortium (W3C), formerly by the International Digital Publishing Forum (IDPF). EPUB 3, the current major version, is based on HTML5, CSS, and JavaScript, which means web accessibility guidelines like WCAG and WAI-ARIA techniques can be applied to EPUB content. Despite this technical foundation, accessibility challenges persist because e-book reading applications do not always pass HTML semantic information to assistive technology APIs the way web browsers do. The DAISY Consortium has been instrumental in integrating accessibility into the EPUB standard, and tools like EPUBCheck and ACE (Accessibility Checker for EPUB) can validate EPUB accessibility compliance.