glGetString -	return a string	describing the current GL
connection

glGetString
	glGetString(name) -> string

const	GLubyte	* glGetString( GLenum name )

name	Specifies a symbolic constant, one of GL_VENDOR,
      GL_RENDERER, GL_VERSION, or GL_EXTENSIONS.

glGetString returns a	pointer	to a static string describing
some aspect of the current GL	connection.  name can be one
of the following:

GL_VENDOR	      Returns the company responsible for this
                    GL implementation.  This name does not
                    change from release to release.

GL_RENDERER	      Returns the name of the renderer.	 This
                    name is typically	specific to a
                    particular configuration of a hardware
                    platform.	 It does not change from
                    release to release.

GL_VERSION	      Returns a	version	or release number.

GL_EXTENSIONS	      Returns a	space-separated	list of
                    supported	extensions to GL.

Because the GL does not include queries for the performance
characteristics of an	implementation,	some applications are
written to recognize known platforms and modify their	GL
usage	based on known performance characteristics of these
platforms.  Strings GL_VENDOR	and GL_RENDERER	together
uniquely specify a platform. They do not change from release
to release and should	be used	by platform-recognition
algorithms.

Some applications want to make use of	features that are not
part of the standard GL. These features may be implemented
as extensions	to the standard	GL.  The GL_EXTENSIONS string
is a space-separated list of supported GL extensions.
(Extension names never contain a space character.)

The GL_VERSION string	begins with a version number.  The
version number uses one of these forms:

major_number.minor_number
major_number.minor_number.release_number

Vendor-specific information may follow the version number.
Its format depends on	the implementation, but	a space	always
separates the	version	number and the vendor-specific
information.

All strings are null-terminated.

If an	error is generated, glGetString	returns	0.

The client and server	may support different versions or
extensions.  glGetString always returns a compatible version
number or list of extensions.	The release number always
describes the	server.

GL_INVALID_ENUM is generated if name is not an accepted
value.

GL_INVALID_OPERATION is generated if glGetString is executed
between the execution	of glBegin and the corresponding
execution of glEnd.