aspell is an open source alternative to ispell, the generic spell check tool available for most Operating Systems. It is included with redhat 7.0.

According to its manual at SourceForge, aspell does a much better job at suggesting words than any other spellchecker (including ispell and the Microsoft suite).

aspell supports multiple dictionaries (currently English, French, Danish, German, Swedish and Faroese dictionaries exist, although any ispell dictionary or even simple word lists can be used). Gaspell is a gnome front end to aspell and provides all the functionality one would expect.

Try aspell here: