I am looking for a simple Captcha MVC for ASP.Net MVC 4. Most I've found has lack of documentation. I tried to use Vyacheslav's Captcha MVC but it has bugs and lack of documentation (image disappears after click refresh, for example). I also tried SuperCaptcha and I discarded it by the same reasons. I discarded PiJiang's EasyCaptcha by the same reasons. The same with BotDetect.
I also tried Google Recaptcha, but it asks to use the captcha in a production environment, and I want to test the captcha first in localhost. Any ideas about a good and simple captcha with good documentation?