Stellarium
Stellarium was originally written by Fabien Chéreau and is run as an Open Source SourceForge project. It is available under the terms of the GNU General Public License (GPL), which strives to make this software and its source code freely open to others as long as they make their modifications free open to others, too.
I reviewed the star name data file back in 2005 which was then commonname.fab. I created a list of suggested changes and applied them to an updated commonname.fab file I still make available here in case they are helpful. I expect they won't be, as the program has continued to grow with an extensive group of volunteer workers.