I\'ve seen this type of animation on a website just when CSS3 key-frames started to gain momentum, but couldn\'t find it nor could I replicate it using CSS or jQuery, and he
The lowest effort approach is probably to use the Morphext jQuery plug-in:
https://github.com/MrSaints/Morphext
It's powered by animate.css, so it's easy to change the animation style of the text.
If you're looking for something a bit more powerful (can specify in AND out animations; animate not just text), there's a spin-off called Morphist:
https://github.com/MrSaints/Morphist