QuickTime
The fastest and most advanced playback software for
panoramas and movies in general has been QuickTime, for
over one decade. Built to accommodate the onslaught of data
compression technologies and advancements. Apple's
QuickTime file format was chosen by the the International
Standards Organization as the basis for the MPEG 4 file
format. Long recognized for it's great backwards
compatibility and forward thinking.
Java
Java is another means to view panoramas. A bit more
CPU intensive and not quite as smooth, but a decent means
for someone on a modem or without QuickTime. Java is easy
to get for nearly any operating system.