A disconstinued project for a faster CPython virtual machine.
Unladen Swallow is a discontinued branch of CPython. It adds a JIT interpreter built on LLVM to CPython's virtual machine. The aim of the project was to make the CPython runtime considerably faster, but the goal of a 5x speed improvement was not met, and so PEP 3146 (Merging Unladen Swallow into CPython) was withdrawn in early 2011.