MatrixScreenSaver is a Mac OS X screen saver. At some point I've used Core Animation but due to performance problems I've discarded this approach. For more details see commit history. Now I use Core Text but the result is still unsatisfactory. So it is more an example how not to make screen savers.
Obviously, the idea for screen saver is not mine, it is taken from the movie The Matrix. Also I've used as the reference Matrix Screen Saver by Kelly Software and The Matrix in Sass by John W. Long.