Finally after long wait, the next stable release of the fun-du, simple
and useful plugin SimpleCaptcha is here!.
Major changes have been incorporated to the plugin in this release
* No Pre-Requisites * RMagick NOT required anymore * FileSystem Usage Removed * No third part dependency(NO API call!) * Works Perfectly with Multiple Clustered Servers * A completely local application based ZERO DEPENDENCY CAPTCHA
And many more…
Read here( http://expressica.com/simple_captcha ) for implementation,
usage and examples.