WordPress.org

yaCAPTCHA is a CAPTCHA plugin for WordPress that helps you block comment spam from automated bots. In order to post comments, users will have to write down the characters that are part of an image. Since it is relatively hard for automated programs to figure out those characters, this will help prevent comment spam from those programs.

Requirements

• WordPress 1.5 or higher.
• PHP 4.1.0 or higher with GD2 library support.
• Theme must support the 'comment_form' action.
• PHP sessions enabled and properly configured.

In case you are wondering, most hosting providers should have those basic requirements in place.

Strengths vs other solutions

• Easy to install
• Does not require Javascript to work
• Broad WordPress version support

Author: remyroy