This project helps improve the web3 ecosystem by providing a single location for developers to access accurate and up to date information for various chains. Being aware of the differing behaviors across chains has important security implications for contracts, so it's important to make sure this data is easily accessible and understandable.

Recent milestones include adding information on metadata, precompiles, predeploys, transaction and signature types, and opcodes for Mainnet, Optimism, and Arbitrum. Currently users can link directly to any section of data for any chain to share that data.

The roadmap and long-term goals are documented in the repository issues (https://github.com/mds1/evm-diff) and broadly are:
1. Finish adding relevant data for Mainnet, Optimism, and Arbitrum. This includes how address computation works, account types, gas data (EIP-1559 parameters, how total transaction cost is computed, etc.), available mempools (public, private via e.g. flashbots, alternatives via e.g. ERC-4337, etc), how block production works, what common utility contracts exist (e.g. Multicall3, create2 deployers, etc) and more.
2. Once all data is added for those 3 chains, we'll have a great template for expanding to add existing chains. 
3. Useful planned features include adding the ability to diff more than 2 chains at once, and a caniuse.com-like view to show all chains that do/don't support a given aspect (e.g. EIP-1559)
4. Long term, it would be great to add an execution playground for each chain where you can simulate code and see how it behaves, like a generalized version of the one on evm.codes