PyPy - fast, compliant alternative implementation of the Python language

PyPy is a fast, compliant alternative implementation of the Python language. It supports most of the commonly used Python standard library modules. Its feature include Just-in-Time compiler, Less memory usage, support Stackless and lot more. PyPy focuses on speed, efficiency and 100% compatibility with the original CPython interpreter. It was conceived as an implementation of Python written in Python, which enables Python developers to hack the implementation.