+GL_EXT_fog_coord
+ Allows specification of a per-vertex fog coordinate instead of
+ having fog always computed from the eye distance.
+
+GL_EXT_secondary_color
+ Allows specifying the secondary (specular) color for each vertex
+ instead of getting it only from lighting in GL_SEPARATE_SPECULAR_COLOR
+ mode.
+
+GL_ARB_texture_env_combine
+ Basically the same as GL_EXT_texture_env_combine
+
+GL_ARB_texture_env_add extension
+ Texture addition mode.
+
+GL_ARB_texture_env_dot3 extension
+ Dot product texture environment.
+
+GL_ARB_texture_border_clamp
+ Adds GL_CLAMP_TO_BORDER_ARB texture wrap mode
+
+GL_SGIX_depth_texture, GL_SGIX_shadow and GL_SGIX_shadow_ambient
+ Implements a shadow casting algorithm based on depth map textures
+
+GL_SGIS_generate_mipmap
+ Automatically generate lower mipmap images whenever the base mipmap
+ image is changed with glTexImage, glCopyTexImage, etc.
+