made a small list, not verified any.
https://tympanus.net/codrops/2009/09/22/21-free-captcha-sources/
https://www.openprocessing.org/sketch/10338
https://github.com/Gregwar/Captcha
made a small list, not verified any.
https://tympanus.net/codrops/2009/09/22/21-free-captcha-sources/
https://www.openprocessing.org/sketch/10338
https://github.com/Gregwar/Captcha