Grawlix lets you comment on Haskell documentation. It's still alpha
quality, but it works. You can read more about the project
on GitHub. Here's how to
Drag this bookmarklet to your bookmarks bar:
Go to some Haskell documentation on Hackage or Stackage. For example,
Click on the bookmarklet in your bookmarks bar.
The comment sections should load in. Pretty much nothing will have any
Type in a comment and click "Submit". You'll bounce through some
redirects, including GitHub's OAuth. You should end up back on the page
you were on.
Click on the bookmarklet in your bookmarks bar again.
Your comment should show up. Hooray!