Telarium was founded in 1984 under the name "Trillium" as a subsidiary of Spinnaker. Legal problems with a book publisher led to the name change in the same year.
With the exception of Shadowkeep, all of the company's releases were adventure games based on works of literature, often made in cooperation with established writers.
Telarium became defunct in 1987, after which Spinnaker, which had already acted as distributor before, continued to market the product range to some extent.
The 1984 released titles by Trillium/Telarium were eventually sold three different ways. In 1984, they were from Trillium and released in double-folded over folders (8" X 10") with seals holding in the contents. In 1984, the folder form remained the same as the games were marketed by Telarium. Around 1986, the folder concept was dumped and the games came in regular flap type boxes (6 3/4" X 9") with a plastic insert tray.