Home > Blogs > Ereaders, formats, and ebook readability

Ereaders, formats, and ebook readability

In plowing though a recent announcement from Microsoft Press about added support for various e-book formats, the relationship between formats supported and readers owned started to loom larger and more important in making e-book buying decisions. Read on to get the scoop on what's what in format-land, and which formats cover the most platforms best.

E-books come in many, many formats, usually including Adobe's Portable Document Format (best known as PDF or .pdf as a file extension) along with a whole slew of other formats, often on a one-per-reader format. Wikipedia, for example, lists no less than 27 different e-book formats in its article entitled "Comparison of e-book formats," and includes numerous familiar items (PDF, CHM, PDF, and even .txt) along with a bunch of stuff I'd frankly never even heard of before.

In a recent blog "New Formats for Free Microsoft Press eBooks" Microsoft makes an interesting case that two formats -- specifically EPUB and MOBI -- deserve special consideration outside the realm of the familiar items I cite in the preceding paragraph, and the numerous proprietary or platform specific formats also available (nicely enumerated in the aforecited Wikipedia article). Here's how they explain the appeal of these two particular formats:

For reading on Kindles, Kindle apps, or the Mobipocket readers for various devices, use the MOBI files. For reading on most other ereaders and ereading apps, including Nook, Sony, and iPad, as well as on PCs, use the EPUB files.

For the record, EPUB is an open standard for electronic books that originates from teh International Digital Publishing Forum, aka IDPF. EPUB merges three IDPF standards including Open Publication Structure (OPS) 2.0 to describe content markup using XHTML or Daisy DTBook; Open Packaging Format (OPF) 2.0 to capture ebook document structure in XML; and OEBPS Contain Format (OCF) 1.0 that packages files in a single container in the form of a renamed ZIP file. EPUB has lots of adherents on mobile device and PC platforms.

MOBI is a common abbreviation for the Mobipocket format, which is built on the Open eBook standard based on XHTML, with optional (but common) use of JavaScript and frames. It even supports SQL queries to embedded databases (great for indexes and searches). MOBI also enjoys broad multi-platform support including PDAs and smartphones, and related products for Windows, Symbian, BlackBerry and PalmOS systems are also available. Amazon Kindle's ADW format is a modified form of Mobipocket with an altered serial numbering system.

Just for grins I took a poke around the various Pearson Web sites to see what kinds of ebook formats they support, and found a plethora of PDFs (as for these free downloads at Pearson Education; and a bunch of DRM PDF offerings right here at Pearson IT Certification). Maybe it's time to ask politely for support for MOBI and EPUB here, too? Pretty please?!