HDRMerge combines two or more raw images into a single raw with an extended dynamic range. The output raw is built from the less noisy pixels of the input, so that shadows maintain as much detail as possible. This tool also offers a GUI to remove 'ghosts' from the resulting image. Please read this short notice before posting.
HDRMerge can import any raw image supported by LibRaw, and outputs a DNG 1.4 image with floating point data. Programs which support these HDR DNGs:
The RawTherapee developers @Morgan_Hardwood and @heckflosse have graciously started helping out Javier Celaya with the project.
Official forum: you're here. Or more specifically, you're in the HDRMerge category of this shared forum. Other libre graphics software share this forum too, so make sure you post in the right category!
Official documentation: https://github.com/jcelaya/hdrmerge/blob/master/README.md
Report bugs and make feature requests: https://github.com/jcelaya/hdrmerge/issues
See and get the source code: https://github.com/jcelaya/hdrmerge