potatoooooo

Oculus checks your comments against the Alibaba Yundun Antispam to see if they look like spam or not and lets you review the spam it catches under your blog’s “Comments” admin screen.
Major features in Oculus 0.1 include:
<ul>
<li>When guest write comments , oculus record user behavior information such as mouse click , mouse move and so on.</li>
<li>Oculus will check the device info of guest to see if they are hacker.</li>
</ul>
PS: You’ll need an <a href="http://www.aliyun.com/product/antifraud" rel="nofollow ugc">Alibaba Yundun Appkey</a> to use it. Appkeys are free for personal blogs, with paid subscriptions available for businesses and commercial sites.

Oculus

Oculus checks your comments against the Alibaba Yundun Antispam to see if they look like spam or not.

Silkalns

WP Chill

Cristian Raiber

A very useful plugin for everyone using WordPress. Adds reCaptcha security to the WordPress login form, register form and comment form. This plugin could help your blog get rid of a lot of spam comments or brute-force attacks.
Nothing gets passed it if the reCaptcha doesn’t validate.
A few notes about the plugin:
<ul>
<li>Supports audio or image captcha types</li>
<li>Can generate the reCaptcha image / audio type in a number of predefined languages</li>
<li>Adds reCaptcha protection to the WordPress login form</li>
<li>Adds reCaptcha protection to the WordPress register form</li>
<li>Adds reCaptcha protection to the WordPress comment form</li>
<li>Adds reCaptcha protection to the WordPress recover password form</li>
</ul>

Uber reCaptcha

This plugin adds the reCaptcha form to the WordPress login form, recover password form, register form and comment form.

Oculus vs Uber reCaptcha