The Jupyter project has a notebook called Xeus for C++.

There is a Go kernel for jupyter/nteract.

https://github.com/gopherdata/gophernotes

There is support for many languages Haskell :: https://github.com/gibiansky/IHaskell Rust :: https://github.com/google/evcxr

https://github.com/jupyter/jupyter/wiki/Jupyter-kernels will give you a more detailed list

Absolutely, see eg: BeakerX [1]

[1] http://beakerx.com/

R notebooks support a bunch. I count about 41 languages in my install, including Go, C++, Fortran and Julia, as well as Python, SQL, Bash, etc.

Go+ is planed to support jupyter and nteract.