U L CAPTCHA is based on PHP to fight with spam. This is very easy to modify to suit your need.
This package also contains some font-files downloaded from 1001FreeFonts website.
Powered By Sourav Ghosh.
Edit !!! 4 months OK, then (my long shot is that my hosting updated libpng)... broken image in <img /> and error msg on captcha.php: ... "Malformed header from CGI script: libpng warning: iCCP: known incorrect sRGB profile" ... Fix ... : Assign sRGB to all background PNGs. This also reduces size of those to like 40%. ---- Now that's an ultra light CAPTCHA. Thanks.
Provides no instructions. readme.txt is only used for self promotion. 2 thumbs down.
Easy, simple, effective, strong CAPTCHA based on PHP and ready to use.