Since 2020, zenbit.eth has undertaken an extensive collaborative research and development initiative with 27 talented individuals with a diverse skill set, from around the world. Together, they have developed over 25 public Open Source Projects, primarily at ETH Global hackathons. These digital solutions encompass seven categories, leveraging advanced Ethereum technologies to address cities´ challenges like transparency, efficiency, and coordination. Our main contribution is the development of over 60 Solidity contracts deployed across multiple EVMs, with ≈28% of these contracts tested on the Optimism mainnet or Op Goerli networks. This has resulted in gas fee expenditure of .116 ETH, bridging ≈10 ETH to the OP mainnet, and locking ≈4k USD in 2 OP chains until 2026.