CPython's the default, most-widely used implementation of the Python programming language. It's written in C. In addition to CPython, there're two other production-quality Python implementations: Jython, written in Java, and IronPython, which's written for the Common Language Runtime, as well as several experimental implementations. CPython's a bytecode interpreter. It's a foreign function interface with several languages including C, in which one must explicitly write bindings in a language oth… (More on Cpython)