GIMP Plugin Registry

This script is by JD Smith and updated for GIMP 2.3+ by Alan Stewart. Main website: http://turtle.as.arizona.edu/jdsmith/exposure_blend.php
After installation, you can access the script from [Toolbox]/Xtns/Photography/Exposure Blend...

exposure-blend makes quick work of blending 3 bracketed exposures into a detailed, realistic, extended contrast image. It has many features to save you the drudgery of assembling contrast blended stacks yourself:  read more »