Anonymous Posting plugin allows anonymous user to write their own posts using special page, no access to WP panel is needed.
Add reCAPTCHA V2 or hCAPTCHA to Contact Form 7
The WordPress contact form plugin inspired by Gutenberg. Drag & Drop online form builder that helps you create beautiful contact forms with just a few clicks.
As nice scroll is a jquery plugin for WordPress site. This plugin will create a nice scrollbar for your site.
Include an Asirra human-interactive proof (HIP) on your comments page,
to prevent automated spam.
An easy-to-use user management plugin that allows user login, reset-password, profile update and user registration with extra fields, all on front-end and many more.
Easy to use Wordpress plugin to insert any Ads to your posts and BuddyPress sections.
The ultimate plugin and service to stop and kill splogs in WordPress Multisite and BuddyPress, from WPMU DEV.
Easy Email Subscription form with secured captcha.
Add Google or Mathematical captcha on wordpress login page
Hercules Recaptcha adds a Recaptcha to the comment form for non-logged in users. It uses the latest Recaptcha API.
Adds CAPTCHA anti-spam methods to WordPress on the comment form, registration form. WPMU and BuddyPress compatible.
Attentive Ads :
Monétiser et Sécuriser commentaires et inscriptions avec les publicaptchas Captch Me.
Monétiser l'accès aux contenus que vous souhaitez valoriser avec le format Access Me.
Monétiser toutes vos pages avec nos formats classiques.
BotDetect Captcha plugin is a powerful captcha protection for WordPress login, lost password, registration, and comment forms.
Captcha Bank is a anti-spam captcha plugin for WordPress forms that adds secure image captcha or math captcha to prevent spam.
Captcha Control gives you more control over your captcha's. You can use the standard Captcha text image, our handy affiliate network to make commission from using our Advertisement Captchas with unique scroll to align Captcha's or use your own Advertisements. Shortcode: [captcha_control] Make sure to grab your API Key from http://www.captchacontrol.com
CAPTCHA Solution is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin.