Forum OpenACS Q&A: Re: DB Smarties Question :) - Inverted Index / Concordance of Unique Words in a Field
I am working on a spell-checker for ad_form that uses ispell/aspell, and have uploaded a (more or less working) patch against 4.7: https://openacs.org/bugtracker/openacs/bug?bug%5fnumber=165
Maybe this is something you could use/improve. I have made a few improvements in the handling of HTML and will upload a new patch in the near future.
This version, however, does not work with the form-builder alone - it needs ad_form, but I have plans on investigating how it could be refactored and implemented as a datatype/widget combo (making it a cleaner implementation and making it available without the need for ad_form).
If you want to help out with this, let me know.