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ePUB and e-Book Development Process at Outsource2india

ePUB is a globally accepted format that is supported by most e-book readers. EPUB and Amazon's proprietary Kindle (.Mobi) have revolutionized the e-book development industry and have fuelled rapid e-book growth worldwide.

The first step in e-book development in the EPUB (.epub) format is to evaluate the available content and understand whether it requires further editing, formatting or OCR (Optical Character Recognition). All such requirements have to be determined before the actual coding/ conversion in the development process.

Usually the book development process for EPUB and various e-book formats requires the creation of a valid XHTML file along with a suitable CSS (Cascading Style Sheet). This is the backbone of e-book coding. The XML files contain all the information, such as the location of the content in the EPUB e-book and the action required. After completion, the coded file is subjected to the validation and optimization process, which is done in accordance with the IDPF (International Digital Publishing Forum) standards. This involves the creation of an OPF manifest file, compilation of the metadata, creation of a dynamic ToC (Table of Contents) file, and finally consolidation of everything into a single valid ".epub" file, also called the "container" file.

The "container" file contains at the very least, the following folders and files:


This is a simple ASCII text file containing the line "application/epub+zip". It provides the e-book reader/ operating system with information about everything in the .epub. This file should precede all files in the .zip file; it cannot be compressed.

META-INF folder:

It holds the "container.xml" file, which points to the position of the book within the Content.opf file. This folder is uniform for every book.

OEBPS folder:

This is the ideal location for all the book content. It includes the:

Images folder: It contains all the images included in the book.

Content.opf: An XML file that has a list of the contents of the .zip file in a chronological sequence and includes:

  • Manifest: A listing of the files in the .epub and their file types.
  • Spine section: It posts the reading order of the content and not the actual files.
  • Metadata: It includes the name of the author, the genre and the publisher of the book, etc. Any additional metadata will require tags such as:
    • dc:title: title of the book
    • dc:language: language used in the book
    • dc:udebtufeur: unique ID code (UID) that is mandatory for every e-book. Alternatively, you may use ISBN.
    • Toc.ncx: Holds the Table of Contents along with navpoint tags. The UID must match the contents of the "content.opf" file, else some e-book readers may display errors.
    • XHTML files: The literal contents of the book are located here, which are simply HTML files that have closing tags attached to every element. Though not mandatory, the best practice is to create a separate .XHTML file for each chapter.

The final EPUB development step puts the e-book in a readable format as follows:

  • Create a new .zip file.
  • Place the uncompressed mimetype file into it.
  • Copy all other files from the OEBPS folder into the .zip file.
  • Rename the .zip extension of the file as .epub.

The validated file is then subjected to quality assurance checks. The optimization process includes testing the file on popular e-book readers such as the Kindle, iPad, Nook and other devices, and tweaking it further, as necessary, to ensure that the e-book functions properly. Now the e-book is packaged and ready for publishing on different platforms.

Our skilled and experienced EPUB development experts can convert books from any format like printed books, text, MS Word, PDF, html and more into the EPUB format.

Contact us today to discuss your e-book development requirements.

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