Dropbox PHP SDK is MIT licensed and intended to be useful both as reference documentation and for regular use. However members of Dropbox developer community have also created alternative libraries in other programming languages.
The Dropbox API allows you to build the power of Dropbox directly into your app. The API provides methods to read and write from Dropbox securely, so your users can bring all their important files with them to your app. Get access to Dropbox PHP SDK Development Kit that provides access to the Dropbox REST API.
Source: Dropbox