This post is now out of date since the forum has moved to a custom solution that integrates with GitHub via OAuth.
Last night I got fed up with the spam that was getting through on the forum and in tickets. While Akismet and the built-in spam filtering in Trac cut out 99.9% of spam, it is frustrating for site participants to get notification emails about spam posts.
In order to cut down on the spam messages even more, I've changed the site to require a user account to post. After finding almost 9,000 spam accounts created on the site, I've also implemented reCaptcha on the registration form.
I apologize for the inconvenience of registering and logging in to participate, but I hope these steps can help keep the site even more spam free and keep the notifications relevant and frustration-free.
If you haven't already created an account, jump over to the registration page and sign up!