With the flood of eReaders on the market and coming to market, it’s interesting to see which format is being supported. To the average eReader owner, the eBook format is a forgone conclusion, but the author/publisher has the challenge of selecting a format for distribution. With so many formats, it seems like there are almost as many formats as eReaders! Here’s a quick look at some popular eReaders and the eBook formats supported.

Amazon Kindle 2 and DX: plain text, PDF, Mobi-Pocket, Kindle
Apple iPad tablet: plain text, PDF, ePub, HTML
Barnes Noble Nook: PDF, ePUB, eReader
Sony Reader: plain text, PDF, ePub, Broadband eBook

Plain text (.txt): ASCII standard text file format which allows interchanging and readability on Unix, Macintosh, Microsoft Windows, DOS, and other systems
Portable Display Format (.PDF): Created by Adobe Systems to represent two-dimensional documents in a manner independent of the application software, hardware, and operating system
ePub (.epub): Format is an open standard for e-books created by the International Digital Publishing Forum (IDPF)
Mobi-Pocket (.prc, .mobi): E-book format based on the Open eBook standard using XHTML can include JavaScript and frames
Kindle (.azw): Developed by Amazon and based on the Mobipocket standard, with a slightly different serial number scheme (it uses an asterisk instead of a Dollar sign) and its own DRM formatting
HTML (.htm,.html): Hyper Text Markup Language which It provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists etc as well as for links, quotes, and other items
eReader (.pdb): Created by Palm Digital Media; The reader shows text one page at a time, as paper books do. eReader supports embedded hyperlinks and images
Broadbank Book (.lrf,.lrx): Proprietary format by Sony, with no known reader software for non-Sony devices

Other eBook formats used by other eReaders include the following:  Fiction-Book, DjVu, WOLF, Tome Raider, and Open eBook.   

There are distinct advantages and disadvantages to each format, but as a potential eReader owner, does the supported format influence which device you buy?