for runtime-checking of available openGL extensions,... Gem has
now included GLEW (the OpenGL Extension Wrangler)
 http://glew.sourceforge.net/

Copyright
   GLEW is originally derived from the EXTGL project by Lev Povalahev.
   The source code is licensed under the modified BSD license, the SGI
   Free Software License B, and the GLX Public License. The automatic
   code generation scripts are released under the GPL.

how Gem uses glew:
 i directly include glew-files, which are
 Base/glew.cpp
 Base/glew.h
 Base/glxew.h
 Base/wglew.h

how to update these files:
 get the glew-sources from http://glew.sourceforge.net/
 untar and chdir into the glew-folder
 run "make extensions"
 (this will fetch the openGL(-extension)-specs from the internet
  and generate the following files: src/glew.c include/GL/glew.h 
  include/GL/glxew.h include/GL/wglew.h)
 copy these 4 files into Gem/src/Base
 rename glew.c to glew.cpp (to get automatically compiled)
 change all include-lines in these files from
 from	'#include <GL/glew.h>'  --> to	'#include "Base/glew.h"'
 from	'#include <GL/glxew.h>' --> to	'#include "Base/glxew.h"'
 from	'#include <GL/wglew.h>' --> to	'#include "Base/wglew.h"'

 once you have downloaded and extracted the glew-sources, you can simply
 run the script ./importGLEW.sh which should do everything for you...

case study:
 ~/src/Gem/src$ cd /tmp
 /tmp$ wget http://belnet.dl.sourceforge.net/sourceforge/glew/glew-1.3.4-src.tgz
 /tmp$ tar xvzf glew-1.3.3-src.tgz
 /tmp$ cd ~/src/Gem/src
 ~/src/Gem/src$ ./importGLEW.sh /tmp/glew/
 
