Short for Irken Pak Technology. Only mentioned in the fan fic / novel / episode of Invader Zim, "Down Came The Rain". Pak Tech is the different upgrades that can be added to the Irken Utility Pak. There are about fourteen up-to-date in the year 2250. One is the ability to walk on top of water.
Little known fact:
The Japanese created the majority of the Pak Tech that They Fight stole.