Activision
Vivendi Games
Activision Blizzard
Lucasfilm Games
Atari SA
Monolith Productions
Electronic Arts
Xbox Game Studios
Bethesda Softworks
Massive Entertainment
THQ
Radical Entertainment
Infinity Ward
Valve Corporation
American video game company
sierragames.com
Sierra Entertainment, Inc. was an American video game developer and publisher founded in 1979 by Ken and Roberta Williams. Wikipedia