I don't know wether this belongs here or in the software section. DIY image processing multi-function utility for Linux.
The manual explains the various modes of operation
FAICS Manual.
Download
FAICS - free (linux) astronomical image calibration and stacking.
Run from extracted folder with RUNFAICS executable or a terminal with;
$ ./faics
If required, first set faics permissions
$ chmod +x faics
Another major project. Curiosity, mainly...
EDIT: Eta Carina unmodded D3300 NEF (submitted for processing by an IIS member some time ago). FAICS and StarTools (scientific color module)