EELS is a Python implementation of the Ethereum Execution Layer, designed to be easily readable and up-to-date with mainnet. It passes state tests and provides a reference for implementing new EIPs. EELS was developed by ConsenSys’ Quilt team and the Ethereum Foundation, with the goal of creating a more programmer-friendly alternative to the Yellow Paper. It provides snapshots of the protocol at each fork, making it easier to understand than EIPs or production clients. EELS can be consumed as a Python repository or as rendered documentation. It is still a work in progress and lacks annotations and explanations, but these will be added over time. EELS aims to complement the Yellow Paper by providing more accessible code examples, such as the comparison of an EVM instruction in both documents. Tests for EELS can be written using standard Python testing tools, and these tests can also be applied to production clients. EELS can also show the differences between forks, making it useful for client developers. An example of an EIP implemented in EELS is EIP-6780, which introduces a variable to the EVM with transaction-level scope. EELS is intended to be the default way to specify Core EIPs, a prototype platform for EIP authors, and the best reference for understanding how Ethereum works. To contribute or prototype an EIP, join the #specifications channel or find an issue in the EELS repository.