With Apple's Keynote presentation software, you have something like a slideshow on steroids. Not only can you create slides, but you can add music, video and animations to your presentations. If you're looking to create "scrolling credits" in your next presentation, you can use one of Keynote's "move" features to accomplish this task.
Start a new slide in your presentation by clicking "New" from the Keynote menu bar.
Select the "Text Box" feature from the menu near the top of the Keynote window.
Enter in the text you want for your scrolling credits. Click "Return" to place spaces between the various pieces of text. Adjust the font and size of the text as desired.
Click on the outer edge of the text box to highlight it, and then drag the entire box to the bottom of the page until the text is not visible.
Click the Inspector icon near the top-right of the menu bar, and then click the "Build" icon near the top of the Inspector to open the Build tools. Choose "Action" from the Build menu.
Select "Move" from the "Effect" drop-down menu. This will cause a second version of your text box to appear on your Keynote presentation, slightly more faded than the original.
Click on the faded text box and drag it off-screen, above the Keynote window. By doing this, you are telling Keynote to move your text box from the bottom of the window to the top.
Select "None" under the Acceleration drop-down menu in the Inspector, and then click the "Duration" menu until it displays "5.00" to make the scrolling text go slower.
If you want your scrolling credits to start automatically following the previous slide, click "More Options" from the Inspector window, click on the line representing your "move," and then select "Automatically after transition" from the "Start Build" drop-down menu.