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.
PPM is a simple format for storing images portable pixmap: color (PPM), grayscale (PGM) and black and white (PBM). These formats can provide an intermediate representation of the data when converting raster image files listed three types between different platforms. PPM format was developed by Jeff Poskanzerom.