Ebooks are produced in many formats, each with their own pros and cons. We believe the best formats to create are epub and PDF. (You can then convert epub easily to Amazon Kindle’s .mobi format, too.)
Epub is an open standard developed by the IDPF. Epub is a way of delivering formatted, reflowable content to ebook readers. In the format wars of ebooks, epub has emerged as the winner. The text in an epub ebook can reflow to suit the reading device or reading software (for example, to suit screen size or a user’s own preferences), but still allows a designer to specify a range of aesthetic and navigational features, including fonts, a clickable table of contents, and embedded sound and video (within certain technical constraints). To read an epub ebook you need epub-capable software.
Epub files can be easily converted into mobi format for the Amazon Kindle. At the time of writing in January 2012, Amazon was rumoured to have at least 80% market share in general-interest ebooks, so depending on your markets, this may be a very significant format for you to work in.
PDF (Portable Document Format) remains one of the most useful and common file formats for documents in the world. It was the first reliable format to enable people with very different computers to look at the same file and see the same thing. Most people use it for sending each other documents that mustn’t change from one computer to another, like contracts or logos. We like it because it’s a familiar format that anyone can open, without any nasty surprises. PDFs can include a surprising number of special features, including hyperlinks, embedded sound and video, and interactive forms. Most people read PDF ebooks in Adobe Acrobat Reader or, when purchased wrapped in Digital Right Management restrictions, with Adobe Digital Editions (ADE).