My post about publishing on the iPad left out a HUGE fourth avenue for small publishers, which is e-books and the ePub format.

ePub is a digital book format based on XHTML. It includes XML, text, and images similar to an HTML page. When you export in Indesign to a digital book, it is exporting into the ePub format. Books in the ePub format allow the user to search, look-up the definition of words, change the size of text, and leave digital bookmarks.

With the iPad, Apple is also releasing iBooks, an e-reader app and bookstore. Amazon has also created a Kindle app for reading their e-books. Books created with the ePub standard can be sold through either establishment. In addition, iBooks will read any ePub-based book on the iPad, including books copied to the device or delivered via e-mail.

ePub and e-books are another way small publishers can get their content into the hands of readers, and it may be the easiest. I’ll post more about how to convert your existing InDesign files into ePub files in future posts.