The SXW file format was originally created for StarOffice Writer, the word processing application for Sun Microsystem's StarOffice suite. Programs that can open SXW files include StarOffice Writer and OpenOffice.org Writer. To open an SXW file in Microsoft Word, it's usually possible by renaming it as a DOC file.
This format is used to store images that have been divided into Y, U, and V color components. In this case, Y corresponds to brightness, and the variables U and V correspond to color information. This format is able to store more accurate color information than the RGB color space. The YUV Color System also allows you to store video files and save a particular sequence of images.