<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.

<p>CheckBot — simple one-click captcha-plugin created for people. It is very easy to use, and look nice, but at the same time, fully customizable, and quite seriously protect your blog from spam.</p>
<h4>Features</h4>
<ul>
<li>Antispam: The plugin uses javascript and randomly generates identifiers and field names, which allows the plugin to automatically filter out fine sent spam.</li>
<li>Support languages: The plugin supports Russian and English languages.</li>
<li>Fully customizable appearance.</li>
<li>The plugin can be used immediately after installation, without additional configuration.</li>
<li>You can configure the output plugin yourself anywhere on the page comments.</li>
<li>If the user is not the correct picture, or even forgot to select it, the plugin will tell him about it, and, just in case it will write a comment.</li>
</ul>
<h3>Help</h3>
<p>You may ask questions at the plugin page – <a href="http://deadblog.ru/checkbot" rel="nofollow ugc">http://deadblog.ru/checkbot/</a>, or write me e-mail – lifeiscoming@gmail.com.</p>


CheckBot

This antispam plugin provides very simple(one-click) and powerful captcha for your blog.

yaCAPTCHA vs CheckBot