Javascript isn't quite what people mean by 'executable documents' - this is about an interface which mixes visible code blocks and results with rich text.
You could certainly base something like that around Javascript, and it would have certain advantages. But the Python world has a lot invested in scientific computing - Numpy, Scipy, and dozens of packages built on top of them. It's also got good integration with other languages, from FORTRAN to R. This sort of scientific computing is where we think the notebook really shines.
Comments
Javascript isn't quite what people mean by 'executable documents' - this is about an interface which mixes visible code blocks and results with rich text.
You could certainly base something like that around Javascript, and it would have certain advantages. But the Python world has a lot invested in scientific computing - Numpy, Scipy, and dozens of packages built on top of them. It's also got good integration with other languages, from FORTRAN to R. This sort of scientific computing is where we think the notebook really shines.