Developed by Mr. Ayan Debnath.
https://code.google.com/archive/p/cb-recaptcha/
LGPL and Creative Commons 3.0 Non Commercial No Derivs License
This software is under strict LGPL and Creative Commons 3.0 Non Commercial No Derivs License. Everyone is permitted to copy and distribute verbatim copies of this software, but changing it is not allowed. * You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). * You may not use this work for commercial purposes. * You may not alter, transform, or build upon this work.