Brainy is a simple PHP class for machine learning. The class helps you to create your neural network. Simple to install and to use. Check it out :)
More info at
https://www.danielefavi.com/brainy-a-simple-php-class-for-machine-learning/
Note: if you are a web developer and you have just started studying AI, Brainy can be helpful to make the first steps in machine learning; but there is no other good reason to use PHP for machine learning!