Image Convertors, Editors, Viewers
reaConverter is a versatile image conversion and processing software that supports over 600 image formats.
If you need a very simple image viewer providing basic processing options, you should try Xlideit Image Viewer.
XnConvert is a nice application to have on your computer for occasional image editing needs and not only.
XnResize acts as a rapid and free image resizer compatible across various platforms.
XnView is a reliable, compact and easy to use image viewer offering support for over 700 file formats for free.