Development kit for the PHP language
Splunk Software Development Kit for PHP
YouTrack PHP Software Development Kit provides set of tools to interact with JetBrains YouTrack.
The Facebook Instant Articles SDK for PHP provides a native interface for creating and publishing Instant Articles.
PHP Development Tools project repository (pdt)
This SDK is deprecated. Find the new SDK here: https://github.com/facebook/facebook-php-sdk-v4
LEGACY: Directus PHP SDK — PHP Software Development Kit