An Electronic Publication, or EPUB, file is the standard type of file used for open-source e-books. The easiest way to open an EPUB file is to use a PDF reader.
EPUB files can be programmed to optimize text for the device used to read the e-book. EPUB files can be opened with any common PDF file reader. The most common of these programs is Adobe Acrobat. EPUB files are very versatile in terms of the ways in which they can be stored. Users can replace the .epub with .zip to create a condensed version of the file. The zip file can be opened by any Windows zip tool.