The ImagiNation Network (INN), also known as The Sierra Network (TSN) and CyberPark, was an early online multiplayer gaming system. Developed by Sierra On-Line in 1989, and first available to the public in 1991, the ImagiNation Network was a unique online gaming network that gave subscribers from all over the U.S. a place where they could "play games, make friends and have fun".