Here is my free plugin to help create closing credits scrolls using Final Cut Pro 6 & 7.
You can use up to four type styles. Two for centred text, one for text that’s aligned to the right – which usually defines roles in productions – and a style for text that’s aligned to the left – which names the actor or person involved.
This image…

is the result of using these settings:

This is a recording showing font colour and sizes of type being changed in real time:
For each style you can instantly change font, size and colour while clients watch. You can also control scrolling speed in pixels per second as well as keyframable speed changes.
The default settings…

…produce this image:

Like Apple’s ‘Scrolling Text’ generator, the ‘*’ character denotes the difference between roles and the names of the people performing the roles.
There are also two heading styles. You can use these two headings styles to do TV-style end credits too. You denote main headings by not including a ‘*’ character, secondary headings are marked with a ‘|’ character at the start (use ‘Shift-\’ to get the ‘|’ character).
Each of these styles have font, typesize, colour and spacing settings.
All the lines have the same line height. This is based on the ‘Names Size’ parameter. You can use the ‘Leading’ parameter in the ‘Global’ section to add or take away space between lines.
Animation methods
There are three ways of animating the credits: ‘From In to Out’ (the speed is set to show the all credits using whatever duration you give the generator), ‘Keyframe % Complete’ and ‘Speed (pixels/sec)’ – the second two options make it easier to synchronise more than one instance of the generator.
If you choose ‘Keyframe % Complete’ as the animation method, set the ‘% Complete’ parameter to 0 at the first frame of the generator, set a keyframe, move to the point you wish the credits to clear the screen and set the ‘% Complete’ parameter to 100%:

You can also set the speed of the animation to a specific speed. This parameter doesn’t keyframe well, so choose a fixed speed and the text will move at that speed. Choosing specific speeds is useful if you have small type that will be shown on interlaced video. Adam Wilt has written the definitive page on scrolling speeds for DV productions. His bottom line is:
Unfortunately, in 525/59.94 [NTSC] the only two decent rates that are slow enough to be read are 120 and 240 (and the latter only on a good day!). 625/50 [PAL] video is better — not only are the roll rates about 20% slower, there are almost 20% more active scanlines in a frame, so in 625 you can roll at 100, 200, and 300 lines/second without straining any eyeballs.
The values Adam uses for lines per second I call pixels per second in this plugin.
If you want to animate other generators, stills and clips using these three methods (for example to add a logo to your credit scroll), use my ‘Move’ plugin.

Installing the plug-ins
Download the ZIP archive of the plugins. Drag the plugins from the ‘Alex4D_closing_credits_v1’ folder to one of two places on your computer:
Your Startup HD/Library/Application Support/Final Cut Pro System Support/Plugins
or
Your Startup HD/Users/your name/Library/Preferences/Final Cut Pro User Data/Plugins/
Restart Final Cut, and you’ll see two new generators in the ‘Text’ section of ‘Video Generators’
To set up a credit list,
1. Either
– Open the Effects Tab in the browser, open the Video Generators folder, open the Text subfolder, double click one of the ‘Closing Credits’ generators
– In the viewer window, click the Generators popup…

… and choose ‘Alex4D Closing Credits’ from the menu

2. The generator will open in the Controls tab of the Viewer. Enter some initial text in the ‘Scrolling Text’ field.
3. Click the Video tab of the Viewer and drag the video onto your timeline to add the new instance of the generator to your timeline.
4. To make changes to the generator you have just added the timeline, double-click it to load that instance into the viewer, click the Controls tab and make changes. You’ll see them update in the canvas (if the playhead is over the generator).
Because Final Cut doesn’t always list all the fonts on your machine in font popup menus, I’ve also included a version of the plugin without font popup menus but with places for you to enter the names of the fonts you want to use.
Visit my Final Cut home for more plugins and tips

Due to the litigious nature of the world, I need to add the following weasel words: These plugins are provided ‘as-is’ and come with no warranty whatsoever. Under no circumstances is the author liable for any data loss or corruption. Use them at your own risk. Save copies of your critical projects when using these plugins. I’ve tested them on Final Cut Pro 6.0.4, but they should work on any version of Final Cut Pro or Express released in the last five years back to FCP4.