ReCAPTCHA MVC lets you embed a CAPTCHA in your web pages in order to protect them against spam and other types of automated abuse.
DEMO and Document => http://recaptchamvc.apphb.com/
The primary features of the library are:
--> reCAPTCHA API verion 2.0 Support
--> The color theme of the widget. (dark, light)
--> The type of CAPTCHA to serve. (audio, image)
--> MVC 4 and MVC 5 Support
This package has no dependencies.