 <p>Hunspell is likely the most famous spell checker around:<br> <a href="http://hunspell.sourceforge.net/" rel="nofollow">http://hunspell.sourceforge.net/</a></p> <p>There are multiple versions of hunspell, but Aspell is an alternative:<br> <a href="http://aspell.net/" rel="nofollow">http://aspell.net/</a></p>