The project 'eth.limo' is focused on enhancing the ENS ecosystem by providing a privacy-preserving ENS gateway, supporting ENS-compatible storage layers like IPFS, Arweave, and Swarm. It offers various services such as on-demand ENS subdomain certificates, a DNS over HTTPS resolver for ENS domains, and infrastructure tools for resolving ENS domains, all of which indicate that it is building on top of ENS.