xyw fundamentally supports two different file formats: .xyw and .xim. === XYW format The XYW file format identifies a xyw source file written with xyw assembly syntax. XYW files must end with a .xyw file extension so that the xyw assembler can automatically process them and assemble them into images. === XIM format The XIM file format identifies a xyw binary image file assembled using the xyw assembler. XIM files have no header, they are normally contiguous streams of bytes corresponding to the assembled instructions and data of a xyw program. XIM files must end with a .xim file so that they can be executed by the xyw runtime automatically.