Cinder is a peer-reviewed, free, open source C++ library for creative coding.
Please note that Cinder depends on a few submodules. The simplest way to clone it is:
git clone --recursive https://github.com/cinder/Cinder.git
Cinder supports OS X, Windows and iOS. It requires Xcode 5.1.1 or later for development on the Mac, and Visual C++ 2013 or later on Windows.
Also be sure to check the User Forum.