After recently seeing The Matrix Reloaded, I got the urge to put that effect on my home page...which I have recently been doing a quick relocation of... Anyway the samples and things that were coming up in the searches I was doing, didn't give me much, so I wrote this from scratch...like me know what you think.
Essentially how the Falling Matrix code works is very simple, you can see the iterative process the development went through, if you download early versions of the code from PlanetSourceCode.
The project started out simply as a code breaking simulation that Hollywood popularizes, the letters just sort of spin randomly until each letter locks in place, the first version I created this is all it did, but it did it in a very flexible way that allowed you to easily change the resulting message.
This was the effect that I was looking for, but it didn't look all that great in practice, so what I did is add multiple layers to the encryption process, each layer remembers the previous layer's value, and the top layer is the one that would randomly select a character. But the randomly selected character was taking a long time to lock in values sometimes...So, I then improved the character selection process, by making vowels more common, and since most of the string was lower case, I made higher odds for a lowercase character to be chosen, but I agree that this selection process could be improved, and sometimes it can take a while for the process to finally decrypt the string.