1.
Animated projection demonstration
http://www.panoramafactory.com/projections/.
2.
Map projection,
http://en.wikipedia.org/wiki/Map_projection.
3.
Perspective projection,
http://en.wikipedia.org/wiki/Perspective_projection.
4.
Cylindrical projection,
http://mathworld.wolfram.com/CylindricalProjection.html.
5.
Equirectangular projection
http://mathworld.wolfram.com/EquirectangularProjection.html.
NOTE: There is no guarantee that these web addresses will remain valid over time. If they are no longer valid, please visit this same web page at The Panorama Factory website to check for updates: www.panoramafactory.com/help/projections_references.html.