ZAP isn't an acronym, it's just a cool name for something that works as the name implies.
Each line is 'zapped', and the lines are separated by the command zap.next;
The default speed in these examples is the normal speed for javascripted animations.
It's simply run as fast as the for() loop allows it to run.

But ZAP doesn't stop there.

A ZAP animation can be boosted - up to times*30.
Several animations run paralell to eachother as separate processes, independently boosted.
We show you an example on this page.

But even though this is a cool party trick, the real reason for ZAP to exist is the fact that animations are beginning to differ too much from one browser to another in regard to speed.
The same mechanism that allows ZAP to be boosted to such a degree, is also making sure that the speed is exactly the same in all browsers.