X PixMap (.xpm)

The XPM format, which stands for X PixMap, is an ASCII text-based image file specification, predominantly utilized within the X Window System environment. Originating in 1989, developed by Daniel Dardailler and Colas Nahaboo at the Bull Research Center, and subsequently refined by Arnaud Le Hors, this format is adept at managing icon pixmap data. A notable feature of XPM is its support for transparent pixels, which is essential for crafting icons with transparent elements.

XPM files distinguish themselves by storing image data as ASCII text, formatted as a Standard C character string array. This strategic approach facilitates straightforward editing via any text editor, seamless insertion of comments, effortless integration as data within C and C++ codebases, and uncomplicated email transmission. XPM files can encapsulate images in black-and-white, grayscale, or full color. While there's no restriction on image dimensions or color count, XPM is typically employed for smaller data sets, such as icons, due to its structure.