The Max Software Development Kit contains the API (headers, source, libraries) for building external objects (plug-ins) in C/C++ for Max. It additionally includes documentation of the API and example projects using the Xcode 6 and Visual Studio 2013 development environments.
The SDK is structured as a Max package. Simply place the SDK in your Max 7/Packages folder to begin working.
It is highly recommended that you test your code thoroughly. One option is use the max-test package.
For support, please use the developer forums at: http://cycling74.com/forums/