eBook Publishing Formats

The following is a comparison of ebook formats used to create and publish ebooks.

Amazon Kindle

Format:     Kindle
Published as:     .azw

With the launch of the Kindle eBook reader, Amazon.com created the proprietary format, AZW. It is based on the Mobipocket standard, with a slightly different serial number scheme (it uses an asterisk instead of a dollar sign) and its own DRM formatting.

eBooks bought on the Kindle from Amazon are delivered over its wireless system called Whispernet so the user does not see the AZW files during the download process. For devices or countries where wireless is not available, AZW files are transfered from a PC to the "Documents" subfolder of a Kindle using the USB cable provided with the Kindle.  The Kindle format is readable on a variety of platforms including the iPad and iPhone.

The Kindle's terms of use forbid transferring Amazon e-books to another user or a different type of device, however books in the AZW format NOT purchased from Amazon may be freely read on other devices provided that they do not have DRM (digital right management). DRM is a necessary "evil"  to protect authors - without it, authors would only ever make a single sale! Unlike paper books, unprotected electronic books can be copied and borrowed with no limits on volume.

EPUB

Format:     IDPF/EPUB
Published as:     .epub

The .epub or OEBPS format is an open standard for e-books created by the International Digital Publishing Forum (IDPF). It combines three IDPF open standards:

• Open Publication Structure (OPS) 2.0, which describes the content markup (either XHTML or Daisy DTBook)
• Open Packaging Format (OPF) 2.0, which describes the structure of an .epub in XML
• OEBPS Container Format (OCF) 1.0, which bundles files together (as a renamed ZIP file)

Currently, the format can be read by the Kobo eReader, Apple's iBooks app running on iOS devices such as the iPhone and iPad, Barnes and Noble Nook, Sony Reader, BeBook, Bookeen Cybook Gen3 (with firmware v. 2 and up),COOL-ER, Adobe Digital Editions, Lexcycle Stanza, BookGlutton, AZARDI, Aldiko and WordPlayer on Android and the Mozilla Firefox add-on EPUBReader. Several other reader software programs are currently implementing support for the format, such as dotReader, FBReader, Mobipocket, uBook and Okular. Another software .epub reader, Lucidor, is in beta.

Adobe Digital Edition uses .epub format for its e-books, with DRM protection provided through their proprietary ADEPT mechanism. The recently developed INEPT framework and scripts have been reverse-engineered to circumvent this DRM system.

DSLibris, a Sourceforge.net project, is able to decode e-books in .epub and .xht format for reading on Nintendo DS systems.

Open Electronic Package

Format:     Open eBook
Published as:     .opf

OPF is an XML-based e-book format created by E-Book Systems.

Mobipocket

Format:     Mobipocket
Published as:     .prc; .mobi

The Mobipocket e-book format based on the Open eBook standard using XHTML and can include JavaScript and frames. It also supports native SQL queries to be used with embedded databases. There is a corresponding e-book reader. A free e-book of the German Wikipedia has been published in Mobipocket format.[11]

The Mobipocket Reader has a home page library. Readers can add blank pages in any part of a book and add free-hand drawings. Annotations — highlights, bookmarks, corrections, notes, and drawings — can be applied, organized, and recalled from a single location. Images are converted to GIF format and have a maximum size of 64K,[12] sufficient for mobile phones with small screens, but rather restrictive for newer gadgets. Mobipocket Reader has electronic bookmarks, and a built-in dictionary.

The reader has a full screen mode for reading and support for many PDAs, Communicators, and Smartphones. Mobipocket products support most Windows, Symbian, BlackBerry and Palm operating systems. Using WINE, the reader works under Linux or Mac OS X. Third-party applications like Okular and FBReader can also be used under Linux or Mac OS X, but they work only with unencrypted files.

Publications in the Mobipocket format directly on the Kindle.

Portable Document Format

Format:     Adobe Portable Document Format
Published as:     .pdf

A file format created by Adobe Systems, initially to provide a standard form for storing and editing printed publishable documents. The format supports features like compression and passwords. Because PDF documents can easily be viewed and printed by users on a variety of computer platforms, they are very common on the World Wide Web. The specification of the format is available without charge from Adobe.

PDF files typically contain brochures, product manuals, magazine articles — up to entire books, as they can embed fonts, images, and other documents.

Since the format is designed to reproduce page images, the text traditionally cannot be re-flowed to fit the screen width or size. As a result PDF files designed for printing on standard paper sizes are less easily viewed on screens with limited size or resolution, such as those found on mobile phones and PDAs.

The Windows Mobile (aka Pocket PC) version of Adobe Acrobat will automatically attempt to tag a PDF for reflow during the synchronization process using an installed plugin to Active Sync. However, this tagging process will not work on most locked or password protected PDF documents. It also doesn't work at present (2009–10) on the Windows Mobile Device Center (the successor to Active Sync) as found in Windows Vista and Windows 7. This limits automatic tagging support during synchronization to Windows XP/2000.

PDF files are supported on the following e-book readers: Mobipocket, iRex iLiad, iRex DR1000, Sony Reader, Bookeen Cybook, Foxit eSlick, Amazon Kindle (1, 2, International & DX), Barnes & Noble Nook, the iPad, PocketBook Reader, Bebook Neo and the Kobo eReader.

eReader

Formerly Palm Digital Media/Peanut Press
Format:     Palm Media
Published as:     .pdb

eReader is a freeware program for viewing Palm Digital Media electronic books. Versions are available for iPhone, PalmOS, WebOS, Android, Symbian, BlackBerry, Windows Mobile Pocket PC/Smartphone, desktop Windows, and Macintosh. The reader shows text one page at a time, as paper books do. eReader supports embedded hyperlinks and images. Additionally, the Stanza application for the iPhone and iPod Touch can read both encrypted and unencrypted eReader files.

The company's web site - ereader.com maintains a wide selection of eReader-formatted e-books, available for purchase and download, with a handful of public domain titles available for free. Those books that aren't free are encrypted, with the key being the purchaser's full name and credit card number. This information is not preserved in the e-book. A one-way hash is used, so there no risk of the user's information being extracted.

The program supports features like bookmarks and footnotes, enabling the user to mark any page with a bookmark, and any part of the text with a footnote-like commentary. Footnotes can later be exported as a Memo document.

The company also offers two Windows/MacOS programs for producing e-books: the Dropbook, which is free, and the eBook Studio, which is not. Dropbook is a file-oriented PML-to-PDB converter; eBook Studio incorporates a WYSIWYG editor. Both programs are compatible with simple text files.

Updated versions of the Palm Digital programs for Apple iPhone/Touch, Blackberry, Mac OS X, and Windows platforms are available on the Barnes & Noble eBooks website. On October 20, 2009, Barnes & Noble announced that their Nook Reader will support the eReader format. eReader format is also supported by the discontinued eSlick, an e-reading device from Foxit Software. It is not currently supported on Barnes & Noble's NookColor.