cleantalk

Anti-DDoS-Lite (Anti-Crawler app) is a small PHP app to protect your site against DDoS attack.

PHP spam protection. CAPTCHA-free alternative

Python spam bot filter. Invisible CAPTCHA alternative

Ruby spam protection for forms. Alternative to reCAPTCHA. No CAPTCHA. Bot filtering.

WP Anti-Spam

C# spam protection for web forms. reCAPTCHA alternative

Security & Malware scan by CleanTalk

Anit-spam extension for Yii framework.

Nodejs API for antispam service cleantalk.org. Invisible protection from spam, no captches, no puzzles, no animals and no math.

UniForce - Universal Security plugin and Firewall for websites

Antispam extension for MediaWiki.

CleanTalk Anti-Spam extension for phpbb v3.1.X & v3.2.X & v3.3.X

Anti-spam MOD for Simple Machine Forum

Joomla 3+ Anti-Spam by CleanTalk

XenForo anti-spam addon.

Module for any CMS

IPS Community Suite 4.0 (IP.Board) anti-spam extension.

MyBB Anti-Spam plugin

Spam bot protection for Yii2 forms. CleanTalk API

Anti-spam plugin for Joomla 2.x