ASP .NET MVC Captcha (MvcCaptcha) is an extension library for ASP .NET MVC2 and MVC3 platforms that brings captcha functionality onboard.

The library delivers:

• HtmlHelper extension method (MvcCaptcha)  to be used in Views

• Captcha validation attribute (ValidateMvcCaptcha) to be used in Models

• MvcCaptcha controller to generate captcha's images

You are welcome to contribute to this project your ideas and bits. 

Please review MvcCaptcha Getting started HOWTO article for the idea howto start using the library.