X Windows Dump Image (.xwd)
The XWD (X Windows Dump) file extension refers to an uncompressed bitmap image format used by the X Window System to store screen captures or "screen dumps" of windows or backgrounds. Developed by the X Consortium, it captures images of graphical user interfaces on UNIX and Linux platforms. The format, originating with X10 and later used in X11, is known for its large file sizes due to the lack of compression. XWD files are typically used for debugging and documentation purposes within the realm of computer graphics.