https://en.wikipedia.org/wiki/X_BitMap https://en.wikipedia.org/wiki/X_BitMap and https://en.wikipedia.org/wiki/X_PixMap https://en.wikipedia.org/wiki/X_PixMap

https://en.wikipedia.org/wiki/X_BitMap https://en.wikipedia.org/wiki/X_BitMap and https://en.wikipedia.org/wiki/X_PixMap https://en.wikipedia.org/wiki/X_PixMap come to mind, but they usually were written by an image editor, not by a program specifically written by the programmer who needed such code in their program.