PSD files are generally a layered file that is proprietary to Adobe PhotoShop. However, this file format has become popular over recent years and many other graphic software programmes (newer versions) have programmed their software to be compatible with this file format (e.g. Jasc Paint Shop Pro 7 and Ulead PhotoImpact 7 & 8.)
NOTE: THIS FILE IS INVISIBLE TO YOUR BROWSER BUT, IF YOU HAVE THE APPROPRIATE SOFTWARE, YOU WILL STILL BE ABLE TO SAVE THIS FILE AND VIEW IT ON YOUR COMPUTER. TO DO THIS, RIGHT CLICK (WINDOWS) AND COPY THE FILE, PASTE IT INTO YOUR DESTINATION FOLDER AND THEN OPEN THE FILE IN PHOTOSHOP OR OTHER PSD COMPATIBLE PROGRAMME.