In September 2007, ePub became an official standard of the International Digital Publishing Forum (IDPF), superseding the older Open eBook standard. Since then ePub has gained widespread acceptance, starting with Project Gutenberg endorsing it as a preferred standard owing to its free and open source features.
ePub: Catching on
The main reason why ePub seems to have caught on as the most favored format is that this open book format is not owned or controlled by any one company or device as is the case with the Amazon Kindle’s AZW format. This enables scope for critique and improvement as is the present case where IDPF has invited discussions on how to improve ePub standards so that it is more holistic and suits the needs of, and leverages the capabilities of newer devices such as the iPad.
Not only has ePub been built on existing standards, but ePub specifications or standards are free to be downloaded by anyone with out any licensing costs or restrictions. ePub file can easily be examined by simply renaming it to a .zip file and opening it with any tool or OS that supports the zip archive format (e.g. Windows XP and above, Winzip, gzip, 7-zip, etc).
A typical ePub file contains the following,
- Metadata, an xml file containing information about the ebook, such as the author, publisher, title and a list of all the other files in this ePub file
- A table of contents for the ebook
- One or more html pages, containing the ebook text
- Any images used in the ebook, such as a cover image, and images that accompany the text, stored in standard formats such as jpeg ePub uses the same standard file formats such as xml, html, jpeg that are used to build the web.
This has one indisputable benefit. Since every modern OS or programming language supports these formats, ePub files can be read on any system with an OS. The technology required to create an ePub reader application is the same as that required to display a web page and any modern computing device, be it a PC or a mobile device is compatible to this technology. Another advantage of ePub is that all text is represented in form of text files that can be easily opened with a text editor, viewed or edited. Also, the ePub format is DRM-free, which means that anyone purchasing an ePub file can be certain that they have full access to the content, and are free to convert it to any other format, transfer and display it on any device, print it and importantly in this case, convert it to speech. Yet, ePub does provide the option of adding DRM as an additional layer, if a publisher so chooses to protect the rights of his ebook/content.
Thus, the advantages of ePub format can be summarized as below:
- Compatible with almost any modern OS based device
- Can be created by common softwares such as InDesign and Quark
- Publishers can reduce the cost of conversion by only creating a single ePub file for multiple distribution channels
- Content can be sold from multiple outlets
- Compatible with most mobile devices including the coveted iPad
Currently, the ePub format can be viewed by Calibre, Adobe Digital Editions (ADE), Stanza, Aldiko, Sony reader, iPad, iPhone. Google too has 500,000 public domain titles in the ePub format. Many countries such China, Taiwan, Germany and France have chosen to use ePub as their primary electronic book format.
One point worth mulling over is the future of ePub. What could the format finally develop into? Will it see more animation options, resizing, cross referencing, linked table of contents and footnotes?
The opportunity is endless. The future of ebooks could well be written by the ePub standard and converting to ePub is an investment in the future.