The UNIX stream editor.  The creator of sed didn't think it's 
interesting to edit empty files, so this needs some kind of input, e.g. 

echo '' | sed -f 99.sed

1{
        s/.*/99 bottles of beer on the wall/
        h
        : x
        p
        s/ on.*//
        p
        s/.*/take :&: down, pass it around/
        /one/{
                s/:.*:/it/