I have written a new server for bbCorrector. (open source free spell checking)
Spelling Results are provided by Google
(same results provided by the Google Toolbar) which also enabled me to provide spelling in 11 languages
Also written in support for custom dictionaries
If you are already using bbCorrector you do not need to reinstall it, simply point it to the new server URL (either HTTP, or the HTTPS proxy) to begin taking advantage of the better spelling results provided by Google. To take advantage of other features create a free account to change your language settings and edit your custom dictionary.
Complete directions at: http://bb.nexstanza.com/
Let me know how it goes!
I didn't write or modify the bbCorrector client, I may not be able to help with certain client issues.