Gnop! is a computer game created by Alex Seropian before founding Bungie with Jason Jones. It was a simple Pong clone written and released nearly 20 years after the original. The name Gnop is Pong spelled backwards. The game was created by Alex Seropian in 1990, almost a year before Bungie's official incorporation. The game proved reasonably popular among Mac gamers because it was free and user-friendly. Seropian also sold the source code for the game for 15 US dollars.
Gnop! was later included in several compilations of early Bungie games, including the Marathon Trilogy Box Set and the Mac Action Sack.