Compiz is Window Manager that has special effects. Now merged with Beryl into Compiz-Fusion, but still available as Compiz Core, without Fusion additions.

Compiz for Puppy 5.3 slacko

More Window Managers with Special Effects
How to Change Window Manager

Compiz homepage
wikipedia page
Puppy Lucid 5.28 + Compiz thread
Compiz on Ubuntu (1 min 36 secs)
List of window managers