Python is the name of a free high-performance compiler originally developed at Carnegie-Mellon University for CMU Common Lisp, it is now used by SBCL, Scieneer, and several other environments as well as CMUCL. Python's main feature is efficient native code compilation using powerful type inference, among other, techniques. It also supports block-compilation as well as the usual incremental.

Python is also the name of a programming language that is not Lisp.