Alibaba Cloud Classic SDK for PHP is supported in PHP 5.6 and later versions. Classic SDK features high stability. This topic describes how to use Alibaba Cloud Classic SDK. For Classic SDK users, we recommend that you start to use Darabonba SDK for PHP at your earliest convenience. For new users, we recommend that you use Darabonba SDK for PHP. For more information about the benefits and usage notes of Darabonba SDK for PHP, see Get started with Alibaba Cloud Darabonba SDK for PHP.