Arbitrum is a unified blockchain platform for building and deploying applications, leveraging Optimistic Rollups to scale Ethereum with faster execution, optimized block times, and efficient data storage. It supports bridging assets via its official bridge, exploring over 900 ecosystem apps like Robinhood, GMX, and Magic Eden, and launching custom interconnected chains through Orbit. With 1.45 million active wallets, $19.21 billion in total value locked, and a 37.1% L2 market share, it emphasizes developer tools, governance participation, and community contributions to advance Ethereum's scalability.
Across Protocol is a cross-chain bridge optimized for speed and capital efficiency, enabling fast asset transfers between Ethereum and its Layer 2 networks including Arbitrum, Optimism, Base, Polygon, zkSync, and Linea. Across uses an intent-based architecture where relayers compete to fill user bridge orders, providing near-instant transfers rather than requiring users to wait for standard bridge finality periods. The protocol is secured by UMA's optimistic oracle for settlement verification. Across is known for having some of the lowest bridge fees and fastest transfer times in the ecosystem, making it popular among users who frequently move assets between Ethereum L2s.
Starknet is an Ethereum Layer 2 scaling network developed by StarkWare that uses STARK (Scalable Transparent ARgument of Knowledge) validity proofs to achieve massive transaction throughput. Unlike EVM-compatible rollups, Starknet uses its own virtual machine (Cairo VM) and the Cairo programming language, offering computational advantages for complex operations. The network supports account abstraction natively, enabling advanced wallet features and flexible transaction signing. Starknet has attracted a significant developer ecosystem building DeFi protocols, gaming applications, and infrastructure tools, with a focus on enabling applications that would be prohibitively expensive on Ethereum mainnet.