Daring Fireball: On the Proprietary Nature of the iBooks Author File Format
Daniel Glazman, co-chairman of the W3C CSS Working Group, has a detailed technical analysis of the iBooks Author file format:
The iba format clearly extends CSS (and therefore EPUB3) to offer the following features:
Template-based layout including special areas (gutter)
Ability to control the size of each column and column gap in a multi-column layout
Something equivalent to Adobe’s Regions and Exclusions.
He thinks these nonstandard extensions are a strategic mistake on Apple’s part:
When a piece of software is so well designed from a UI point of view and could become such an attractor in terms of usage, I feel this is a totally wrong strategy. Opening up everything and using only carefully chosen standards and matching the version of WebKit used by Safari would have given an immense and almost unbeatable competitive advantage to Apple, would have attracted even more people to the Mac platform and would have turned the iBooks Store into the primary online choice of publication for all new books.
It should surprise no one that the co-chair of a W3C working group deems standards compliance to be more important than does Apple. And he may well be right that it will prove to be a strategic mistake. But it’s worth noting that the e-book market leader, Amazon’s Kindle, uses a proprietary format.