Well nodeJS is doing a decent job by having the same language on the server side as on the clientside.
css and html are both markup-lanugages and I find it very strange to add turing-completeness to a markup language.
well there are examples where this IS the case, look at LaTeX for example.
But having html as the frontend, and both clientside and serverside javascript as the backend is the closest that we can get at this moment.