most (not all, some contributions are QTVR-only due to historical reasons)
many, but depends on photographer's choice of file upload (newer event = more likely to work) and your device's capabilities. You may experience slow playback, distorted images or unexpected browser quitting if there is only limited memory/GPU power available.
The last social of the 2007 IVRPA Conference (at the University of California Berkeley campus), took place in the courtyard outside of La Val's Pizza and La Burrita Mexican on Euclid Avenue where everyone who was still around gathered for pizzas and beers. Taken at what was the magic moment (8:36 PM) with the courtyard lights coming on and setting the right mood. After gathering the IVRPA community around for a group picture, and with some coaxing (smile, lean right, lean forward) this was the resulting self-portrait, close-up and personal. It was a great conference and I was glad to have attended and be among other passionate panographers.
Latitude: 37° 52' 32" N
Longitude: 122° 15' 37" W
Precision is: Medium. Nearby, but not to the last decimal.