The formal idea of FreeSoftware was started by RichardStallman who founded the [http://www.fsf.org/ Free Software Foundation] and wrote (or organized the writing of?) the GNU General Public License, otherwise known as the [http://www.fsf.org/licenses/gpl-faq.html GPL].
The basic tenant of the FSF is that that all software should be free (as in the sense of freedom, not necessarily as in the sense of no money).