Sierra On-Line, also known as On-Line Systems from 1979 to 1982 and Sierra Entertainment from 1982 to 2015, develops and publishes a variety of video games for home consoles, mobile devices and computer systems. Some properties include the "Leisure Suit Larry" series, the "SWAT" series and the "King's Quest" series.
Sierra Entertainment was originally founded in 1979 by husband and wife team Ken and Roberta Williams in Simi Valey, California. The company eventually moved operations to Oakhurst, California, but later moved to Fresno, California. During its early years, it became known for creating graphical adventure games for home computer systems. In the early days of video games, computers had very limited graphical capabilities, resulting in many games using text as both the primary visuals and the main user interface mechanism.
During the 1980s and 1990s, Sierra continued to create numerous games for computers as well as the emerging home console market. However, as console gaming slowly overtook computer gaming as the dominant platform, Sierra faced numerous financial difficulties. In 2014, the studio was purchased by Activision Blizzard, joining a large pool of California-based and international video game developers. Activision Blizzard re-launched Sierra Entertainment as a developer and publisher focusing on downloadable content for home console and computer gaming.