GLEXT is a Win32 DLL with header and linker library, designed using Microsoft Visual Studio 2012. It implements all publicly available OPENGL extensions as static functions, that can be directly called without the danger of running into NULL pointer exceptions.
It can be freely used and distributed or modified. And as source is also available, the API can be recompiled with other versions of Visual Studio. And source can also be recompiled with Other C/C++ API for different OSes...