Early Augmented Reality Applications

Augmented Reality (AR) has been a widely-known concept since last year. Actually however, AR has been around for over four decades.
It would be worth it to look back on the major AR applications of the last few decades.
This posting is about AR applications that predate the iPhone and Android platforms.
The first augmented reality application was invented by Ivan Sutherland in 1968. He called it "Ultimate display" and he believed that the ultimate display might let us understand our own natural world better. It is basically a Head-Mounted Display (HMD) AR application.

The second major augmented reality application was made by Boeing. In addition, Tom Caudell started to use the word "Augmented reality". The flight simulation is one of the fields that has used augmented reality actively so far.

ARToolKit is the third major AR application. It was originally developted by Dr. Hirokazu Kato, and its ongoing development is being supported by the Human Interface Technology Laboratory (HIT Lab) at the University of Washington, HIT Lab NZ at the University of Canterbury, New Zealand, and ARToolworks, Inc, Seattle.

ARTag is also another tag-based AR application like ARToolKit. The good thing about this application is that you can avoid one of the main problems that many programmers face: the array problem in matching the locations of real objects and virtual objects. ARTag came out many years after the original ARToolkit, and they improved the tag detection capabilities compared with ARToolkit.

References :
http://econsultancy.com/blog/5293-augmented-reality-ar-the-technology-is-now-market-ready
http://www.hitl.washington.edu/artoolkit/
http://www.artag.net/rev1.html