This page is equipped with a "Page-Enter" meta tag:

<meta http-equiv="Page-Enter" content="revealtrans(duration=2,transition=23)">

• There are 25 different Page-Enters, all of them are defined in the meta tag
• The content attribute describes the effect.
• There are 24 revealtrans Page-Enters, and 1 blendtrans Page-Enter
• The duration property describes how many seconds before the effect is completed.
• The transition property describes which actual effect your document will have, from 0-23

Feel free to look at the source code