Comment by musicale

I was replying to GP.

You could certainly replace bash and traditional Unix shells with something else. My favorite attempt is scsh (though mainly for the "acknowledgements" section of its reference manual.)

But I'm in favor of a Unix/Linux command shell and scripting language that has type and taint checking for command arguments, and which differentiates between code and data. Typed data pipes could be nice as well.

However, Unix/Linux isn't (yet) designed for those features. For example exec() doesn't type check command arguments.