If you’re using v6.5 animated gifs will work in a frames page when set as the background image, referring to it from image resources. I’m not sure about previous versions.
You can also set multiple iomages to randomly cycle and change each time the page is opened with the following code:
Index := @Text(@Integer(@Random * 22) + 1);
Add this code as the background graphic/resource formula for the page. Then add your images (jpegs, gifs, whatever) in image resources and give each a successive number (in this case from 1 to 23). After reopening the page the images will cycle through. I use animated gifs for our office db around holidays. It breaks the monotony.