Modern programming languages are expected to offer high-level abstractions at reasonable speed. Especially scripting languages like Ruby, PHP and Python are highly dynamic and flexible, which makes performance optimizations difficult to implement.
While Python 3 offers a lot more features compared to Python 2, these features don't always improve runtime performance. In the pystone benchmark, execution speed has even decreased over the recent years.
PyPy, a relatively new implementation of Python with a focus on performance tries to improve the situation - with obvious success. Code execution is much faster thanks to the built-in just in time compiler which optimizes code at runtime.
In this talk I give an overview of PyPy and how it works internally. Also I talk a bit about PyPy STM, a new approach for parallel code execution that can take advantage of modern multi-core hardware.