Welcome to the FSPViewer web pages

FSPViewer is a free viewer for spherical (equirectangular) panoramic images. It is designed for viewing local (hard-disk, network or CD) high resolution panoramic images at full screen and with very high image quality. It uses advanced interpolation algorithms to show you smooth images without losing sharpness.FSPViewer has been available for many years as a Windows-only program. Version 2 has been entirely rewritten and now the program is available for many operating systems.I can also embed the rendering engine in other programs to add panoramic image viewing to custom software. Feel free to contact me if you are interested.

Source: Welcome to the FSPViewer web pages