Well...Maybe it's an unnecessary library in Kohana,but I still try to make it be module. The original source from http://www.phpcaptcha.org/,so It's GNU LESSER GENERAL PUBLIC LICENSE
呃…或許這個模組在Kohana是多餘的,但是我還是把他做出來了= =,他一樣是用http://www.phpcaptcha.org/的原始碼修改的,所以授權一樣是LGPL