the interpreter executes user commands and
scripts.  However, most of the underlying functionality is written in
a low-level language like C or Fortran.
</p>

<p>
The two-language model of computing is extremely powerful because it
exploits the strengths of each language. C/C++ can be used for maximal
performance and complicated systems programming tasks. Scripting
languages can be used for rapid prototyping, interactive debugging,
scripting, and access to high-level data structures such associative
arrays.