hfst (open source rewrite of the Xerox finite state toolkit) includes negation:

    $ echo 'a b
    c b
    c d*' | hfst-regexp2fst > ab.fst
    $ echo 'c ?+' | hfst-regexp2fst >cdotplus.fst
    $ hfst-intersect ab.fst cdotplus.fst | hfst-expand -c3
    cb
    cd
    cdd
    cddd
    cdddd
    $ hfst-expand -c3 ab.fst
    ab
    cb
    c
    cd
    cdd
    cddd
    

The regex syntax is a bit quirky due to backwards compatibility with lexicons written in XFST, see https://github.com/hfst/hfst/wiki/Regular-Expression-Operato...