Different publishers support different formats, so unless you plan to publish and market your ebook yourself, you need to consider the formats supported by each publisher, and how best they relate to the viewing devices normally used by your target market.

The e-book publishing industry is very fragmented in terms of what ebook formats they regard as true ebooks. No tools exist now to export e-book formats to PDF or OpenDocument. For this reason, it is a good idea to have your source document in an OpenDocument format, such as the new OASIS standard used in OpenOffice.

If the text is in ASCII or HTML format, it easily can be converted to plain-text or PDF format by using a text browser such as w3m or programs such as html2ps.

Popular eBook Formats

There are many formats for eBooks today. The most popular are:

Ebook Format	Pros	Cons
Plain Text / Word**	Readable and printable by all	No security and limited formatting in plain text.
Adobe Reader [.pdf]	Multimedia & Links to Web Good publishing features Can be read and printed by most	Standard version has no security against unauthorised distribution. Pro version is expensive. Poor formatting Hard to read on mobile devices
Adobe Ebook [.pdf]	Formatted for smaller screens	May not work on Palm OS
Microsoft Reader [.lit]	Free basic authoring program or advanced commercial version Can be read on Windows PC, Windows Tablet and Pocket PC devices. Simple to use. Supports ClearType fonts for easy on-screen reading. Supports searching, highlighting, bookmarks, notes, changing font size, and text-to-speech. Rader program is free.	Does not support printing. Requires Windows OS
Gemstar	Read on Gemstar Reb Series, Rocket eBook, Windows PC Reader	Not printable
hiebook	Free Authoring software even for commercial purposes Easy to use.Add bookmarks. Read on hiebook reader or Windows PC. Supports mp3, games.	Must load on PC [not MAC]
HTML	Supports all multi-media.	No security features Easily copied, modified & distributed by others
.exe [Instand Ebook]	Secure HTML with multipmedia and www links. Most authoriing programs <$100. Easy to navigate.	Readers cautious of viruses Most only run on Windows computers. Require copy formatted in HTML.
Mobipocket [.prc]	Supports most handheld platforms, and Windows PC computers. Text can be searched. Good navigation tracking and bookmarking.	Does not support printing. Authoring software expensive [Basic at $150 and $1,000 for Professional Edition. No reader for Macintosh or Unix/Linux systems
Palm Doc [.pdb]	Compressed plain text with bookmarks - work on most devices. Supports changing font size and bookmarking.	Basic format does not support text formatting. Encryption is not supported.
Palm Reader	Works on any Palm OS device. Font sizes can be changed. Bookmarking is supported. Security encryption supported.	Does not support printing. Free authoring software for PC or Mac unencrypted books. Encrypted books are only available through authorized outlets.
Kindle [Mobi with DRM]	Reader uses a free Sprint Mobile connection to access ebooks	Uses Amazon proprietary format with very restrictive DRM Reader is more expensive than others

** Some publishers still release books in Plain Text [.txt] and Microsoft Word [.doc] – avoid Microsoft 2007 as most people cannot access this version yet. Use Word 2000 or 2003.

Most believe that Text, Work and PDF versions are not true ebooks. However, as many readers prefer not to download .exe files or to require proprietary readers, the PDF version is becoming the most popular. PDF's also have the advantage of being able to be printed and whilst they afford limited security against copying the text and graphics, they are freely distributed.