A QR Code is a matrix code (or two-dimensional bar code) created by Japanese corporation Denso-Wave ( a subsidiary of Toyota) in 1994. The "QR" is derived from "Quick Response", as the creator intended the code to allow its contents to be decoded at high speed.
Other software companies have created 2D codes that work much like QR codes, with Microsoft being the most notable. Microsoft developed their own software to create codes known as MS tags. Unlike QR codes, which can be read by a number of different readers, MS tags can only be read by the Microsoft Tag Reader.