<p>yaCAPTCHA is a CAPTCHA plugin for WordPress that helps you block comment spam<br />
from automated bots. In order to post comments, users will have to write down<br />
the characters that are part of an image. Since it is relatively hard for<br />
automated programs to figure out those characters, this will help prevent<br />
comment spam from those programs.</p>
<h4>Requirements</h4>
<ul>
<li>WordPress 1.5 or higher.</li>
<li>PHP 4.1.0 or higher with GD2 library support.</li>
<li>Theme must support the ‘comment_form’ action.</li>
<li>PHP sessions enabled and properly configured.</li>
</ul>
<p>In case you are wondering, most hosting providers should have those basic<br />
requirements in place.</p>
<h4>Strengths vs other solutions</h4>
<ul>
<li>Easy to install</li>
<li>Does not require Javascript to work</li>
<li>Broad WordPress version support</li>
</ul>
<h3>Thanks</h3>
<p>Thanks to Kruglov Sergei for creating KCAPTCHA, his pretty good CAPTCHA. You<br />
can visit KCAPTCHA website <a href="http://www.captcha.ru/en/kcaptcha/" title="KCAPTCHA
website">here</a>.</p>


yaCAPTCHA

yaCAPTCHA is a CAPTCHA plugin for WordPress that helps you block comment spam from automated bots.

leo108

<p>Ajax Fancy Captcha is a jQuery plugin that helps you protect your web pages from bots and spammers. We are introducing you to a new, intuitive way of completing “verify humanity” tasks. In order to do that you are asked to drag and drop specified item into a circle.</p>
<p>通过拖动解锁来实现评论验证。能够有效防止垃圾评论、机器人评论。</p>


Fancy Captcha

Fancy Captcha is a jQuery plugin that helps you protect your web pages from bots and spammers. 通过拖动解锁来实现评论验证。

yaCAPTCHA vs Fancy Captcha