ECL is typically used for integration into C. CLASP is a derivative for deep integration with C++. There are a bunch of other to C transpilers, some are in-hous

ECL is typically used for integration into C. CLASP is a derivative for deep integration with C++. There are a bunch of other to C transpilers, some are in-house. For example PTC's large Creo Design CAD system uses an in-house maintained Common Lisp to C compiler.