OpenCaptcha is a software I made that creates CAPTCHA images (`Are you a robot?` images). It is currently used to generate over 2,000 CAPTCHA images per month, as can be seen below (under jpeg requests).

Below are examples of CAPTCHA images generated by this software.

The software is based on code that is over 20 years old, initially published in 2004.

(www.codeproject.com/Articles/5947/CAPTCHA-Image)

Also I created a documentation website (www.opencaptcha.io) to encourage people to use the software.