OpenGL has been around quite a long time. It is currently the only 3D graphics that can claim ubiquitous support on the 3 major desktop platforms, as well as the 2 biggest mobile platforms.
Partly because of it's age, OpenGL is a bit clunky to use. C++ can help to hide some of the grunge of the C-based API, but C++ also brings the potential for a different kind of grunge. C++11 helps out here, because its Standard Library provides a more complete standard to write solid code against than previous versions of the language.
The framework presented here is called XGL. The X means cross in this case, as in motocross being shortened to moto-x, GL is the shortened form of OpenGL, thus we mean to indicate cross-platform OpenGL. We're aware this is not a unique usage of this particular 3 letter combination. However given it's already been used more than once we figured one more usage is acceptable.