ADE is available on Android. Kobo support is supposed to be good. And Gitden Reader looks interesting.

epubtest.org has an ePub 3 support matrix, but coverage is spotty and it looks like they need more contributors to keep the information current.

Note that Amazon now has a tool for building Print Replica and accepts that via KDP. Almost certainly it doesn’t support audio or video, and Kindle platform offers little in the way of accessibility support for Print Replica/PDF.

PDF has several ISO standard specs. But FXL is driven by IDPF (NOT ‘IPDF,’ ha-ha), and history with ePub spec. So they were naturally biased to solutions that derive from web technology, as ePub does. And IPDF includes major publisher participation, so I have to assume they are getting what they want out of it.

No, Print Replica is not available via KDP. But there really aren’t any people self-publishing textbooks, which is the only type of reading Print Replica is used for. These same books generally offer rental terms as well. Companies like Chegg also offer PDFs-as-textbooks.

There is one very ‘major ebook retailer’ who, it appears, has no plans to support FXL ePub (Amazon). In the meantime, they do in fact sell PDF files (‘Print Replica’), and today announced launch of ‘KDP Kids’, which includes authoring tools that are dead simple to use, compared to InDesign. One of the main ‘use cases’ for FXL ePub is supposed to be children’s books.

One can certainly argue that FXL ePub is far more flexible and powerful than Amazon’s truly primitive fixed layout format, but it remains to be seen what the market will want. I’m not sure I would bet against Amazon. I don’t think consumers are exactly clamoring for the type of rich-media ebook experience that FXL ePub is theoretically capable of. Economically, what Amazon is doing seems very pragmatic. Will there be enough demand to support the effort involved in putting high quality, compelling FXL publications together? We’ve been through some of this with ‘multimedia’ ebooks, which have not exactly taken off in any big way.

Moreover, FXL ePub has many of the same limitations as PDF when it comes to mobile devices: text is not resizable, there are many shapes and sizes of screens and a fixed layout cannot adjust to all of them. The experience of reading FXL ePub on a 4″ screen is not going to be any more pleasant than a PDF is. Quite possibly it will be less pleasant: at least you can reflow PDF in many cases (will app developers have to figure out how to reflow FXL too?). PDF typography is better. What screen aspect ratio do you design for? 4×3? 16×9? What text size is big enough?

Another use case is ‘photography books’. That at least is something that FXL should be better at than PDF. But perhaps mobile apps are an even better platform for this.

Ironically it is the leveraging of web technologies that is often touted as a strength of FXL ePub. It’s also ironic that InDesign has emerged as the leading creation tool, given its lack of any foundation in web technologies. The concept of ‘fixed layout’ seems quite antithetical to web technology, but is quite natural to InDesign.

Open specifications are no guarantee of interoperability, as we have seen over many years of web development. At least it has to work on Readium and iBooks. Maybe that is not so impossible, as those two that must account for 90% of what is not Amazon.

I will have to leave it to others to chime in with ‘what is better’ and what the market opportunities are. I can’t seem to overcome my skepticism at this point. But I do look forward to developments, and to future learnings.