On-line Systems was based in Coarsegold, California. They developed and published arcade style games for Atari 8-bit and Apple II systems.
Founded in 1979 as On-Line Systems by Ken and Roberta.Williams.
In 1980 On-Line Systems changed their name to Sierra On-Line, Inc..
In 1998, Sierra split up its organization into 4 sub-brands and corporate divisions: Sierra Attractions (For casual games such as poker), Sierra Home (For home/lifestyle software), Sierra Sports (For sports games) and Sierra Studios (General publishing division).
In January of 1999, Sierra and its affiliates were acquired by Havas, S.A.
In 2008 ownership of Sierra was transferred over to Activision. Later that year, Sierra was closed down for possible future sale.
On August 7, 2014 Sierra Entertainment was revived.