Dungeons and Dragons Online, and Lord of the Rings Online. They also produced the Asheron's Call games.
Founded in Boston in 1994,Turbine was, until now, the largest privately-held online games studio in North America.
"We have been looking to expand access to our online worlds to more players and more markets," said Jim Crowley, president and CEO of Turbine.
"This acquisition is very exciting because it allows us to expand globally while continuing to focus on creating spectacular online games that our loyal fans and players have come to expect."
This appears to be the latest in a series of acquisitions Warner has made over the past couple of years - are they trying to 'compete', do you think?