is a format developed by the International Digital Publishing Forum. It is characterized by the XML- and XHTM-based optional use of CSS styling. The main feature of this format is the use of reflowable text (word wrap) which makes it possible to adapt the image to different device displays. The ePub file is a zip-archive with an .epub extension.
The extension allows you to save audiovisual and textual information as a presentation or a slide show. Is used solely for viewing the created presentation and has no editing capabilities. It’s based on the XML format and can be opened with PowerPoint 2007 and newer versions. The file may be viewed by the users who do not own a commercial PC version of MS PowerPoint but who could still view the presentation using PowerPoint Viewer.