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.
PGM is a storage format for grayscale images. Files in this format can be opened using software: ACDSee Photo Manager 14, ACD Systems Canvas 15, Corel PaintShop Pro X4. This type of file can be edited with a text editor. PGM files can be in two versions: P2 / P5. P2 are readable, P5 - to binary formats.