Photosynth2 SDK contains libraries, code samples
for developing your own 3d synth viewer with annotations and connections.
You can insert a Photosynth2 viewer into your own page and control it or customize it's appearance.
You can display and create highlights (annotations) with the Photosynth2 viewer. You can learn more about the different annotations storage available by reading the documentation.
Once you've created synths and added annotations you can connect them to create a virtual tour.