ispell

International Ispell (an interactive spelling corrector)

Ispell corrects spelling in plain text, LaTeX, sgml/html/xml, and nroff files. [x]Emacs and jed have nice interfaces to ispell, and ispell works from many other tools and from the command line as well. No ispell dictionaries are included in this package; you must install at least one of them ("iamerican" is recommended by default for no good reason); install the "ispell-dictionary" package(s) for the language(s) you and your users will want to spell-check. It's a good idea to install "word list" package(s) for the same language(s), because they'll be used by ispell's (L)ookup command.