Spranto http://www.spranto.com There are two versions, Lite (Free) or Profesional (Commercial). Yate client http://yateclient.yate.ro/ Free Mirial Softphone http://www.mirial.com/ Commercial PacPhone http://www.pacphone.com/ NetMeeting http://www.microsoft.com/downloads/en/details.aspx?FamilyID=26c9da7c-f778-4422-a6f4-efb8abba021e&displaylang=en Ekiga http://ekiga.org/
