man0xff

Nocaptcha is free intelligent CAPTCHA service that can deliver a majority of real users from solving a CAPTCHA riddle with the same protection level from spam scripts. The service has been successfully used in our internal projects and on sites unrelated to Mail.Ru.
This plugin adds integration with Nocaptcha Mail.Ru service. Widget can be easily added to different forms:
<ul>
<li>Comment form</li>
<li>Login form</li>
<li>Registration form</li>
<li>Lost password form</li>
</ul>
Visit for more information:
<ul>
<li><a href="https://nocaptcha.mail.ru" rel="nofollow ugc">Official site</a></li>
<li><a href="https://nocaptcha.mail.ru/docs" rel="nofollow ugc">Documentation</a></li>
</ul>

Nocaptcha Mail.Ru

Adds integration with Nocaptcha Mail.Ru service - free intelligent CAPTCHA service.

Maxim

We hope you want to increase user’s traffic in your blog and we want to help you reach this goal. You may know that users are registering on web-sites in case only they really need something, 
but lots surfers just close page when see that registration is required. Somebody just lazy, 
somebody doesn’t want to spend time to register… or cares about security and personal data. So, how to engage user to login? Really, easy – just let users login with one of social network login, 
like Google, Facebook, Twitter and more. Earlier you must have developers skills to enable on your site OAuth, but now we care about it for you. All that you need – follow few simple steps: 1. Install and enable this plugin, go to settings page 2. Login to www.quicklogons.com and enter profile 3. Add site settings, put callback url and save 4. Get site key and secret, put them to plugin settings and save 5. Enjoy! Those steps are enought to start. It would take only few minutes, 
but you will give surfers more freedom and comfort and as result increase traffic.

Quicklogons

Fast and easy get users logged in on your web-site with bunch of OAuth providers like Google, Facebook, Twitter and more.

Nocaptcha Mail.Ru vs Quicklogons