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.