Infinitely many categories can be added to the gallery. New categories are automatically added to the left-side column. If more categories are added than can be viewed, a scroller (the small up and down arrows) are automatically added. Categories and images are added using an XML configuration file, which can be edited using any standard text editor, like Textpad (www.textpad.com). Images are loaded externally, from non-progressive JPG files. Please note that the files must be saved as non-progressive JPGs. Infinitely many images per category are possible. Images are automatically arrayed in the right-side panel. If more images are added than can be fit in the viewable area, top and bottom scrollers (the little up aand down arrows) are added automatically. All gallery sounds are stored as external MP3 files. 100% of the Flash 2004 Pro. (Flash 7) source code is included with your purchase. If you can't find an XML configuration for what you need, then it's likely that you'll be able to do it yourself by directly editing the Flash source code (assuming knowledge of Flash programming). Over a dozen configuration options are available in the external XML configuration file. Please note that not all of these options are available for this gallery, but many are. More options are added for each release.