Photosynth is still around. The current version is more limited than it used to be, it only supports straight lines and circular panoramas. But they're working on a more impressive update. Here's a preview http://photosynth.net/preview/view/df869f96-2765-4939-8eb3-2... You can zoom in an out, pan around, and hit 'c' to see a wireframe.
Edit: you can also make Deep Zoom images offline in the Image Composite Editor, but that's been around for a long time. https://research.microsoft.com/en-us/um/redmond/groups/ivm/I...