DirectX 11 compute shader Versus OpenCL.

I know OpenCL is a standalone GPGPU standard which is much different from the compute shader in DirectX which is tightly bundled to graphic pipeline. It seems to me that Compute shader is more like a subset of OpenCL.

But are there any features/functions that Compute Shader supports while OpenCL lacks of? I mean detailed comparison of functions/features, but not general concepts.

I have read through the directX document and searched over internet but have no clue.
I am newbie on graphics. Anyone can shed me some light on this issue?

Thanks a lot.