The problem of cross-chain interoperability has evolved into more than just moving crypto assets from one chain into another. Multiple protocols, such as Layer Zero, Chainlink CCIP, Alexar Network, Hashi, and others were developed in order to tackle the Web3 communication problem as the whole, which includes cross-chain invocation of smart contracts, synchronization of data between chains, and other use cases. The high number of new protocols designed (or still being developed) has led to a variety of designs: some protocols require a network of relayers and oracles, while others rely on a separate network (such as, Alexar). These designs are relatively new and not yet well understood. In this talk, we systematize and compare multiple designs and implementations of cross-chain protocols. We use examples of Layer Zero, Alexar Network, Hashi to compare properties of two groups: security and non-security. Security properties include: crypto-economic incentives, liveness assumptions, sustainability, denial-of-service tolerance, and others. Non-security properties include: cost for end user, latency of cross-chain call, and others.