*Have at it, developers.
http://sproke.blogspot.com/2009/11/augmented-reality-resources-for.html
"One aspect of AR DevCamp is building and hacking stuff. Augmented Reality has been around for quite some time and there are many software projects and some hardware projects. I'll cover what I found after a couple of days of searching. This isn't intended as a comprehensive list, rather its a sampler of what's available right now.
"Marker based Augmented Reality
"Augmented Reality has been around for some time; but until the relatively recent advent of smart phones with compasses and GPS, the major focus of open source AR software has been around markers that register images superimposed on the a camera view.
"The canonical implementation is ARToolKit from Washington University which has spawned implementations in multiple programming languages. In addition to ARToolKit derivatives, other marker based AR software are Goblin and Goblin XNA which was developed using C# and .NET, Simplified Spatial Target Tracker (SSTT) Visualizer developed by Hartmut Seichter in C++, and Studierstube Tracker which is conceptually similar to ARToolKit but is a different code base designed for mobile phones...."
