is there any downloadable GL API reference?

OpenGL OpenGL: Basic Coding
1

browsing internet is not convenient for me sometimes, so i prefer downloadable references in PDF or CHM format. is there any?

2

There are the specs at
http://www.opengl.org/registry/
But they’re a tough reading

3

You also have the reference cards available at:

http://www.khronos.org/developers/specs/