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.
This format was created by Nokia for use in its proprietary phones. A bitmap image was used to transfer image files between devices over a wireless connection. It was mainly used when exchanging multimedia text messages that support inserting pictures.