   ? include files for OpenGL210 to OpenGL310 upgrade ?
  I'm a bit confused about where to get OpenGL include files going forward (into OpenGL v3.00 and beyond).  We're about to upgrade our engine from OpenGL210/GLSL120 to OpenGL310/GLSL140, so now is the time to make changes in our practices.At the moment we get our (gl.h, glext.h, glx.h, glxext) headers for our linux implementation from the nvidia driver package.  I'm having trouble figuring out where these files are being included from on our winxp64 development environment.On both platforms we include the glee.h and glee.c source code files (no lib files).I am a bit confused already about the consequences of including different versions of the GL, GLX and WGL .h files, and now that OpenGL v3.00+ suggest these gl3-type include files (?and gl3/* directories?), I'm especially confused.Also, we hope to upgrade one feature at a time from the OpenGL210 API features in our current engine, to the new OpenGL310 API features in our upgraded engine.  The question is, what include files (and other techniques) are required to keep OpenGL210 API features available even as we upgrade other parts of our code to OpenGL310 API features (even though some of those features may be removed in the OpenGL310 API)?Any tips are welcome, and do link to any good articles about this process.   
  Since you are talking about Windows, don't include glx.h and glxext.hFor moving to GL 3.0 or 3.1, the usual glext.h includes all the definitionshttp://www.opengl.org/registry/api/glext.hLook at the #ifndef GL_VERSION_3_0 sectionThe gl3.h file you mentioned is a stripped file. Anyone can take glext.h and remove all the old stuff. Nothing special here.   