Richard Phillips

SpamScrubber helps block bots and spam submissions by: 
– Adding a customizable delay to all form submit buttons. 
– Obfuscating form actions for non-JavaScript users. 
– Adding a honeypot field (with customizable label) to trap bots. 
– Blocking direct POSTs by requiring a JavaScript token. 
– Providing admin stats for various spam attempt types.
<h3>License</h3>
This plugin is free software released under the GPLv2 or later.

SpamScrubber

A simple and robust anti-spam plugin that adds a submission delay, JavaScript token, and a honeypot field to your site's forms.

Otto Kekäläinen

Viljami Kuosmanen

This plugin fights comment and registration spam on your website. This plugin is based on the Open Source WP No-Bot plugin at http://www.compdigitec.com/apps/wpnobot by Compdigitec.
This plugin is authored by <a href="http://seravo.fi/" rel="nofollow ugc">Seravo Oy</a>, which specializes in open source support services and among others is the only company in Finland to provide <a href="http://seravo.fi/wordpress-palvelu" rel="nofollow ugc">WordPress Premium Hosting</a>.
Source available at https://github.com/Seravo/wp-spam-question-filter

WP Spam Question Filter

This plugin fights comment and registration spam on your website.

SpamScrubber vs WP Spam Question Filter