This page displays information about installed OpenGL implementation. OpenGL (for "Open Graphics Library") is a cross-platform, hardware independent interface for 3D graphics.
GLX is the binding for OpenGL to X Window system.
DRI (Direct Rendering Infrastucture) provides hardware acceleration for OpenGL. You must have a videocard with 3D accelerator and properly installed driver for this.
Read more at the official OpenGL site http://www.opengl.org