The UK Governmental preferred abbreviation for Free (Libre) and Open Source Software.
The French distinction between Libre and Gratuit is more convenient and precise than the American "Free as in speech, not as in beer" or whatever English phrase might be used, and considerable disinformation and some confusion exists under the English word. The Open Source Initiative was in large part a response to that, and has slightly less emphasis on variation from the software copyright licences of the FSF/GNU.
There is a degree of congruence of the ideals of medicine and science with those of the Free/Libre/Open Source Software movement or communities.
http://www.linuxmednews.org/ (A central FLOSS on-line periodical)