This is a monochrome image format with a bitmap structure. It is used to store images of icons and cursors in the X Window System graphical user interface, which is used for remote connections. The structure of an XBM file consists of simple text written in the C programming language.
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.