Key Information

Keep your eBook projects simple. Avoid complex layouts and formatting, only use simple tables and don't use invisible topics. Only a..z, A..Z, 0..9 and _ are permitted in topic IDs in eBooks!

File extension:

.epub

Format:

A single zip archive file containing the XHTML and XML files and other components. Additional configuration files and special settings are required for compatibility with Apple iBooks® on Apple's iOS devices (iPad, iPhone and iPod Touch).

Platforms:

Viewable on any platform or device for which an ePUB reader is available. Apple iBooks® on the iPad, iPhone and iPod Touch, Sony Reader, Windows, Apple OS X, Linux, Unix, Sony Reader, mobile phones and many more.

Typical use:

Reading books on hardware eBook readers. Although a large number of software readers are available, only a very small number of users actually read books on computers. The huge majority use mobile devices like the iPad to read eBooks.

Distribution:

ePUB eBooks can be distributed directly. Even if you are targeting Apple iBooks® devices, you can distribute your ePUB eBooks directly to your customers and they can install them on the device themselves.

Easiest distribution method:
Put the eBook file online and post the URL to the file as a QR code, which can be generated by Help+Manual. Users then scan the QR code with their device camera and the book is downloaded and loaded automatically by their ePUB eBook reader app.

Table of contents:

Yes, not supported by all readers

Keyword index:

No

Full text search:

Yes, but search functionality depends on reader

Context-sensitive help:

No support for context-sensitive help, you cannot make direct calls to specific topics in the help

Popups:

No

Multimedia:

Video is supported in iBooks® on Apple iOS devices (iPad, iPhone, iPod Touch). Some other devices may support video but don't depend on it. Most don't.

Printable by user:

Yes, but print functionality depends on reader

Pros:

Single-file, universal cross-platform format already supported by many software and hardware readers. Large number of ePUB eBooks already published, already a universal standard. Generally intuitive handling (depends on reader).

Cons:

This is really a dedicated format for books in electronic form. Best for books that users read in the same way as a printed book. Search but no index, simple formatting only, video only in iBooks®.