OpenTK is a set of bindings to OpenGL, OpenCL and OpenAL. This is not the main repository, just a temporary import to allow Mono developers to make changes to this module. Please do not contribute changes here, contribute them to the upstream maintainers at http://www.opentk.com
The official website migrated from opentk.com to opentk.github.io a while ago, so the link in the project description should be updated accordingly.