The Sixaxis (trademarked SIXAXIS) is a wireless gamepad produced by Sony for their PlayStation 3 video game console. It was introduced alongside the PlayStation 3 in 2006 and remained the console's official controller until 2008. The Sixaxis was succeeded by the DualShock 3, an updated version of the controller that, like the DualShock and DualShock 2 controllers, incorporates haptic technology – also known as force feedback. A Sixaxis controller can also be used with PSP Go via Bluetooth after registering the controller on a PlayStation 3 console. The DualShock 3 was originally intended to be bundled with the PlayStation 3 in time for the console's launch. However, Sony was in the midst of appealing a decision from a 2004 lawsuit involving patent infringement claimed by Immersion. The two companies were at odds over the haptic feedback technology used in earlier PlayStation controllers. The legal battle led to a decision to remove the vibration capabilities from the PS3 controller's initial design, which became known as Sixaxis. The term "sixaxis" is also used to refer to the motion-sensing technology in PlayStation 3 controllers. It is a contraction of "six axis", which refers to the ability to sense motion in all axes of the six degrees of freedom. The name is a misnomer because there are only three axes: X, Y, and Z, which allows six degrees of freedom (rotation about each axis and translation along each axis). It is also a palindrome. History At E3 2005, Sony showcased their "boomerang" design for the PlayStation 3's controller. Accompanied by much criticism, most of which were for its looks, this design was later abandoned. Sony later stated that the original controller "was very clearly designed as a design concept, and was never intended to be the final controller, despite what everybody said about it". At E3 2006, Sony announced that the boomerang design had been replaced by the Sixaxis; a wireless, motion sensitive controller, similar in overall design to the earlier PlayStation DualShock controllers. The controller was bundled with all new systems from launch, until the introduction of the 80 GB (CECHKxx, CECHLxx & CECHMxx) model, which substituted the Sixaxis with the new DualShock 3 which added a vibration feature while retaining the design, features and functionality of the Sixaxis. The Sixaxis controller was later phased out and replaced by the DualShock 3 controller completely and is no longer being produced in any region.