The OpenGL specification includes some patented technology. It's more accurate really to state that modern computer graphics are founded on some technologies that are patented, and any and all graphics APIs worth using are going to rely on implementations licensing or violating those patents.
This is one of the reasons why your Open Source Linux drivers on mainstream distros are going to be indefinitely stuck on OpenGL 2.1.
This is a pretty well known fact and frequently mentioned topic on the boards here. I take it you're new. Welcome.