The Sierra Network (TSN), later rebranded as the ImagiNation Network (INN), was an online service launched in 1991 by Sierra On-Line. Developed beginning in 1989, the service offered subscribers an online space to play games and socialize, billing itself as a "cyberspace theme park."

History

TSN was conceived by Ken Williams, co-founder of Sierra On-Line, who saw potential in expanding the gaming experience beyond single-player adventures to a more social, interactive medium. The service launched in 1991, enabling real-time interactions and gameplay among users across different locations. He also took an interest in Prodigy, an early online service he called a "preview of the future." Prodigy was the first platform to integrate text with a graphical user interface and content designed for a mainstream audience. It required only a power source and telephone line, with a built-in modem.

By November 1992, the company had invested $10 million in developing the service, aiming for 50,000 members by March 1993.

Inspired by Disneyland's themed lands, Williams envisioned The Sierra Network as a digital theme park with distinct areas, aiming to create a space that vertically targeted different audiences and interests.

  • The Shadow of Yserbius: A role-playing game set in Mount Yserbius' dungeons, filled with monsters and puzzles. It combined traditional RPG elements like turn-based combat and character development, paving the way for future online games with its mix of gameplay and social interaction.

thumb|alt=Screenshot of FaceMaker interface used to customize player avatars|FaceMaker was among the first to offer customizable avatars on online platforms.TSN also introduced FaceMaker, a tool allowing members to design a virtual "face" or avatar for their online identity. These avatars, which could be seen during games or chats, offered customization options for gender, age, and style, enabling users to tailor their digital representation to their preferences.

The need for a dial-up connection limited potential growth to users within the continental United States. This decision resulted in the renaming of the network to "The ImagiNation Network". In 1994, AT&T completed its investment by purchasing the remaining stake for $40 million, taking over network infrastructure and customer acquisition and billing processes to address the operational challenges previously faced by Sierra.

AT&T planned to invest $5 million into developing new games for the platform.