It is an open source third party viewer for Second Life and OpenSim grids.
Dolphin Viewer 3 is an open source third party viewer for Second Life and OpenSim grids. The program has all the new features from the original Second Life 3.0 viewer, such as mesh and avatar body physics. It also offers Avatar and object derendering options.
This viewer was a lot better than that of Firestorm, which should have stuck with being just Phoenix Viewer.