HDR (High dynamic range imaging) is a technology to superimpose a set of same images with different exposure levels using software. This no doubt is an art using technology and photography in which technology is in the forefront. A lot of photographers use this nowadays. There are a handful of commerical and open-source software available for this. As I am Linux and Open-Source enthusiast using Ubuntu based Linux Mint, I will talk about Luminance HDR which was called Qtpfsgui which is hosted in SourceForge.
Kelby Training has some nice video tutorials about HDR.
For more information:
Luminance HDR (Qtpfsgui): http://qtpfsgui.sourceforge.net/
HDR Imaging: http://en.wikipedia.org/wiki/HDRI
All the views expressed are my own and may differ from person to person. Copyright for the