Xbox One is a home video game console developed and marketed by Microsoft to compete with the PlayStation 4 and Nintendo Wii U. Moving away from the Xbox 360's PowerPC architecture the console features an AMD processor built around the x86-64 instruction set and launched with the Kinect 2. It was released on November 22nd 2013 for $499.00, which would equate to $536.42 today.
November 22nd, 2013 Source: wikipedia.org
Originally released in a bundle including the new Kinect 2.0.