The Flat Four OpenGL component provides a common, simple interface to get OpenGL up and running on Windows, MacOS X, and Linux/X11. It is implemented as a fully-managed .NET assembly: one binary, many platforms with no recompiling.

If you are looking for a full-featured graphics system, you might want to check out the Graphics component (hardly full-featured at this point, but I'm getting there) which provides (someday) mesh- and shader-based rendering over both OpenGL and Direct3D.

The OpenGL component is intended for developers who want to write small, lightweight 3D applications that can run on multiple platforms.  It requires the Tao.GL module, which provides a binding to the full API, and a windowing framework such as the Flat Four Platform component (see example), System.Windows.Forms (see example), or any toolkit that can provide a window handle.

The OpenGL component does not include a mapping to the full OpenGL API (use Tao.GL for that) or any type of rendering objects (use the Graphics component instead). Like I said, small and lightweight.