Py-EVM is a new implementation of the Ethereum Virtual Machine written in python. It is currently in active development but is quickly progressing through the test suite provided by ethereum/tests. I have Vitalik, and the existing PyEthereum code to thank for the quick progress I’ve made as many design decisions were inspired, or even directly ported from the PyEthereum codebase.
Py-EVM aims to eventually become the defacto python implementation of the EVM, enabling a wide array of use cases for both public and private chains. Development will focus on creating an EVM with a well defined API, friendly and easy to digest documentation which can be run as a fully functional mainnet node.