We are planning to use RabbitMQ from PHP, and we decided to go with php-amqp, because it supports PHP 5.2. The only problem is i can't find a proper documentation for this PECL library
It is sad to say, but official php-amqp documentation (https://www.php.net/manual/en/book.amqp.php) was removed as it was obsoleted. For now you can look through stub files and tests.
I'm really sorry that we don't write proper documentation and examples yet.
If you will have further questions about php-amqp extension feels free to post more questions here or contact me personally.