Source : Free On-Line Dictionary of Computing

shelfware
     
         /shelfweir/ {Software} which is never used and so
        ends up on the shelf.  Shelfware may be purchased on a whim by
        an individual, or in accordance with corporate policy, but not
        actually required for any particular use.  Alternatively, it
        may be software that has been developed (unlike {vaporware}),
        but is never released as a product -- a common occurrence at
        {DEC}.
     
        [{Jargon File}]
     
        (1997-07-20)