Since QR codes seem to be one of the hot new technologies in the library and museum world, I decided to do a little research on them (I am a librarian after all!) Here's a brief introduction into the world of 2D code technology:
QR (quick response) codes are two-dimensional images used to represent data, similar to a barcode. They were originally developed by Japanese auto parts manufacturer Denso-Wave in 1994, for tracking parts. Denso-Wave still owns the patent on the technology (which has its own published ISO standard) but allows for their license-free use.
QR codes are an improvement over barcodes mostly because of the amount of data they can encode. While barcodes can only hold 20 digits worth of data, QR codes can hold up to 7000 digits and 4300 alpha-numeric characters and can be as small as 2 centimeters square (although the more data encoded, the larger the resulting image will be).
Originally QR codes required dedicated scanners to read them, but the advent of smart phones with built-in cameras have recently brought the technology into much greater usage. Currently, they are commonly used to link print and broadcast media to online content (usually by encoding a URL), but can also be used to share simple text data such as a phone number or text-only message, or more complex information like a command that can play a song automatically if you have it on your computer, or bring you to a site that prompts you to purchase the song if you do not already own it.
Similar technologies to QR codes include open source Data Matrix codes, used by the U.S. Department of Defense, and the proprietary Microsoft Tag (which features color codes that can store more than the other, black-and-white ones.)
Although non-Asian countries have been slow in adopting QR code technology (Pepsi launched what is now acknowledged as the first large-scale QR code marketing campaign in 2008), it has recently gone mainstream, with companies such as HBO and Fox launching QR campaigns. The museum and library world have also found use for the technology, linking their physical collections with their expanding online offerings.
Also helping to launch the tech into the mainstream was Google’s recent launch of a URL shortening service which also provides users a simple way to create QR codes from any URL.
“UKOLN | Briefing Documents | An Introduction to QR Codes.” (http://www.ukoln.ac.uk/cultural-heritage/documents/briefing-61/html/)
ISO - International Organization for Standardization, and ISO. "ISO/IEC 18004:2006." 01 Sept. 2006. (http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=43655)
Lardinois, Frederic. “Microsoft Tag: The CueCat Returns on Your Mobile Phone.” ReadWriteWeb 8 Jan. 2009. (http://www.readwriteweb.com/archives/microsoft_tag_the_return_of_the_cuecat.php)
Milliot, Jim. "QR Codes Tie Print, Online Marketing." Publishers Weekly 256.38 (2009): 4. (http://www.publishersweekly.com/pw/by-topic/childrens/childrens-book-news/article/71-qr-codes-tie-print-online-marketing-.html)
Nguyen, Maria. "What you need to know about QR codes." Sydney Morning Herald, The 05 July 2008: 2. (http://www.drive.com.au/Editorial/ArticleDetail.aspx?ArticleId=56159)
Perez, Sarah. “The Scannable World, Part 3: Barcode Scanning In The Real World.” ReadWriteWeb 26 Sept. 2008. (http://www.readwriteweb.com/archives/the_scannable_world_barcodes_scanning_in_the_real_world.php)
Perez, Sarah. “iCandy: Make QR Codes That Play Music.” ReadWriteWeb 16 Jan. 2009. (http://www.readwriteweb.com/archives/icandy_make_qr_codes_that_play_music.php)
Siegler, MG. “Goo.gl’s Awesome Easter Egg To Instantly Turn Any Link Into A QR Code.” TechCrunch 30 Sept. 2010. (http://techcrunch.com/2010/09/30/googl-easter-egg/)