The Missed Opportunity for Interactive Book Content

EPUB is the format most e-books are distributed. (A file with the .epub extension.) EPUB is technically a zipped webpage under the hood. The EPUB 3.3 specification defines support for audio, video, and scripting. It leaves scripting support optional for reading systems. In theory this should have lead to e-books—especially technical or textbooks—to use the technology to better ilustrate their points. Very few e-book readers support the full EPUB 3.3 spec, however. Apparently Apple Books and the Thronium epub are the most complete. But the Kindle mobile and desktop apps only have partial support1, and Amazon’s Kindle e-ink devices, Kobo e-readers, and Adobe Digital Editions don’t support those parts of the spec at all. The interactive-textbook demand is real. That’s why technical publishing has mostly routed around EPUB. They still offer their books in EPUB or PDF formats, but O’Reilly and others have developed their own browser-based platforms: executable notebooks, companion…