Creating Augmented Reality experiences in the web today is possible thanks to a number of options. The solution that grants the wider reaching capability in the web is undoubtedly Flash-based Augmented Reality. FLARToolKit is the most widely used Flash-based AR library with the support of a large developer community and many websites with example applications. FLARToolKit is the Flash Actionscript (v3) version of ARToolKit which can be used to quickly develop web-based AR experiences.
FLARToolKit recognizes a visual marker from an input image and then calculates the camera orientation and position in 3D world and overlays virtual graphics on the live video image. FLARToolKit has support for all of the major flash 3D graphics engines (Papervision3D, Away3D, Sandy, Alternativa3D).
FLARToolKit is provided under a dual license model (GPL and commercial). Inglobe Technologies and Artoolworks provide commercial licenses for it. The open source version of FLARToolKit can be downloaded here.