UPDATE Now you can set an option in the new settings page (titled “Herc Sentiment” in the admin bar) to auto-approve positive comments, or un-approve negative comments.
Hercules Sentiment Analysis uses PHP Insight (https://github.com/JWHennessey/phpInsight) to determine whether comments, posts, and post titles are positive, negative, or neutral. This will help bloggers respond to readers who have concerns faster (or delete negative comments if necessary), as well as know what sentiment they are portraying with their post titles and content.