Much of this document was written by Tom H Anderson and some material was compiled from other sources in the Apigility realm.
Tom was the original author of zfcampus/zf-apigility-doctrine and has created many supporting libraries for Doctrine in Apigility. He contributed much to the early development of Apigility and continues to give to open source in PHP.
As soon as Apigility was announced developers were asking for Doctrine support though none of us really knew what that ment. What was created serves as a strong platform for an ORM based API.