Sometimes people write Lisp code and use translators to C or C++. Some of that code then will be maintained in C / C++. Some of these tools were custom developed, but there existed also specialized Lisp to C translators, which produced 'maintainable' code.

For example the first version of the .net garbage collector was written in Common Lisp and then translated to C++. Since then it was maintained and enhanced in the C++ version.

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