Xbox was first released on November 15, 2001 in North America, February 22, 2002 in Japan, and on March 14, 2002 in Europe.
Since Microsoft owns the intellectual property rights to the hardware used in the Xbox 360, they can easily switch to new fabrication processes or change suppliers in the future to reduce costs.
With the launch of the Xbox 360, Microsoft's online gaming service, Xbox Live went through a major upgrade, adding a basic non-subscription service, Silver, to its already established premium subscription-based service, Gold.
John Carmack stated at QuakeCon 2005 that the Xbox 360 has "the best development environment I've seen on a console".
Updated emulation profiles can be obtained through Xbox Live, by burning a CD with profiles downloaded from Xbox.com, or by ordering an update disc from Microsoft.
Microsoft has stated that they intend to release more emulation profiles as they become available, with a goal of making the entire Xbox library playable on the Xbox 360.
The Xbox CPU also contains ROM storing Microsoft private encrypted keys, used to decrypt game data.
While the first Xbox's graphics processing unit was produced by NVIDIA, the Xbox 360 uses a chip designed by ATI called Xenos.
Xenos contains 48 unified shader units, which are capable of both vertex and pixel shading operations. This is in contrast to older graphics processor designs which utilize separate specialized units for these tasks.
The console features 512 MB of 700 megahertz GDDR3 RAM on a 128-bit bus.
