If you want to use Mesa and native OpenGL in the same application at the same time you may find it useful to compile Mesa with name mangling. This results in all the Mesa functions being prefixed with mgl instead of gl.
To do this, recompile Mesa with the compiler flag -DUSE_MGL_NAMESPACE. Add the flag to the other compiler flags in Make-config (if using the old-style build system) or in src/Makefile if using GNU autoconf/ automake to build Mesa.