BSD, MIT and WTFPL are all on the list of officially verified Free Software licenses: http://www.gnu.org/licenses/license-list.html and are thus "Free Software".

Open Source, similarly, is defined as software released under a license that follows the definition of Open Source Software ( http://www.opensource.org/docs/osd ). The OSI also has a list of approved licenses: http://www.opensource.org/licenses/alphabetical