not ready for prime time

not ready for prime time adj.  Usable, but only just so; not
   very robust; for internal use only.  Said of a program or device.
   Often connotes that the thing will be made more solid {Real Soon
   Now}.  This term comes from the ensemble name of the original cast
   of "Saturday Night Live", the "Not Ready for Prime Time
   Players".  It has extra flavor for hackers because of the special
   (though now semi-obsolescent) meaning of {prime time}.  Compare
   {beta}.