QR code

QR codes (Quick Response) are a type of 2-dimensional bar code which is currently very popular. Originally designed for industrial use in tracking items as they move around a warehouse or factory, they are currently mainly used to provide hyperlinks in ads, articles, and signs which somebody with an appropriate reader (such as apps for a smartphone) can use to retrieve what is generally a URL linking into the Web, though other kinds of content can also be stored. SPARQCode is one of the methods used for standardizing the encoding of URLs and other specific kinds of data within a QR code. A company named DENSO-WAVE, which originally invented the codes, owns a trademark on the name "QR code", as well as various patents covering the technology, but allows free use of them as long as the standards are followed. They run the official QR Code website.

Software

 * Review of barcode scanner apps
 * Android app to read UPC and QR codes to look up product info/prices and other info coded or linked in bar codes
 * Bar Code app (iOS)
 * ZBar app (iOS)

Developer libraries

 * ZBar bar code reader library: cross-platform
 * zxing (Zebra Crossing) (barcode library for Java, ported to some other systems)
 * barcode.php

Utilities

 * Bar code generator: QR
 * Online barcode generator (supports many different formats)
 * Bar code creator

Other links and references

 * QR code (Wikipedia)
 * QRpedia (QR code with specially-formatted URL for language-independent Wikipedia links)
 * Official QR site
 * Reed Solomon Codes for Coders - Wikiversity tutorial
 * Barcode contents
 * WTF QR Codes
 * Google Glass hacked by a simple QR code
 * Mobile Web Tour at Walkway Over the Hudson (uses QR codes)
 * Stamping Chinese banknotes with censorship-busting QR codes
 * qrquine: QR code containing program code that reproduces itself
 * Keep your data safe from the apocalypse in an Arctic mineshaft (uses QR codes)