<p>WP Spam Hitman is based on set of rules and concept of hitpoint. With right set of rules and hitpoint level you can eliminate most or even all of the spam on you blog.<br />
It works in 3 modes – Delete, Moderation, Spam and is quite customizable.<br />
It allows to set unlimited set of rules – both – simple words and regular expression patterns. It’s simple but powerfull tool for fighting with spam.</p>
<h3>Changes</h3>
<h4>0.7</h4>
<ul>
<li>added – Message ‘%tags%’ – you can place information from comment in your message for spammers</li>
<li>fixed – bug – now you can change message for spammers</li>
<li>change – default message for spammers changed to less offensive</li>
</ul>
<h4>0.6</h4>
<ul>
<li>fixed – bug with displaying message on modes moderation/spam</li>
<li>added – version number displayed on the right of plugin name in options</li>
<li>added – version checker – it checks if you have the newest version available and if not – tells you about it providing link to the newest one</li>
</ul>
<h4>0.5</h4>
<p>First public release.</p>


WP-Spam-Hitman

WP Spam Hitman allows you to fight with spam using set of patterns and hitpoints. It also allows you to decide what's going to happen to the spam

Silkalns

WP Chill

Cristian Raiber

<p>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.</p>
<p>Nothing gets passed it if the reCaptcha doesn’t validate.</p>
<p>A few notes about the plugin:</p>
<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.

WP-Spam-Hitman vs Uber reCaptcha