 FreeBSD developers maintain at least two branches of simultaneous development . The -CURRENT branch always represents the " bleeding edge " of FreeBSD development . A -STABLE branch of FreeBSD is created for each major version number , from which -RELEASE are cut about once every 4 – 6 months . If a feature is sufficiently stable and mature it will likely be backported ( MFC or Merge from CURRENT in FreeBSD developer slang ) to the -STABLE branch . 
