Decor Decor is a System extension which allows you to replace the boring desktop pattern with a background picture of your choice. Decor handles StartupScreen, PICT, GIF and JPEG files. It has a lot of great features; for instance, you can ask it to select pictures from a certain folder, and to pick a new one every 10 minutes. Decor is now free. Decor works fine under MacOS 7, 8 and 9. (Under 8.