Redirect to a Thank-You Page After Commenting
Sends first-time commenters to a page of your choice after they submit a comment, instead of back to the post.
Snippet Library
Comments snippets for WordPress
Snippets for WordPress comments: fight spam, close comments on old posts, remove the website field, change the comment form and moderate faster. For bloggers and publishers who want useful discussions without the noise.
Reject Comments Submitted Too Fast
Rejects comments sent within a few seconds of the page loading, which only bots manage, using a signed timestamp in the form.