Optimism (OP) is a layer-2 blockchain that operates on top of Ethereum, aiming to scale the Ethereum ecosystem by using optimistic rollups. This means transactions are recorded on Optimism but ultimatley settled on Ethereum, benefiting from Ethereums consensus mechanism. The Optimism Foundation, a nonprofit organization, leads Optimism with the goal of growing the Optimism ecosystem. The foundation is funded by donations and grants and strives to produce infrastructure that promotes the growth and sustainability of public goods.

Optimism operates with a focus on simplicity, pragmatism, and sustainability. It aims to keep its code as simple as possible, using proven Ethereum code and infrastructure when possible. The ecosystem is driven by the real-world needs and constraints of its team and users, aiming to build iteratively and implement features gradually. Optimism uses optimistic rollups and leverages the consensus mechanism of Ethereum to scale the network. Blocks are constructed and executed on Optimism (L2), while user transactions are batched up and submitted to Ethereum (L1). Transactions are submitted to Ethereum without direct proof of validity and can be challenged for a certain period of time. After this period, a transaction is considered final.

Optimism's potential use cases involve enhancing Ethereum's scalability and efficiency. This includes supporting faster and more cost-effective transactions (compared to transacting directly on an L1) for Decentralized Finance (DeFi) platforms, enabling minting of Non-Fungible Tokens (NFTs), and providing infrastructure for Decentralized Autonomous Organizations (DAOs). It also caters to a better user experience in blockchain-based gaming and various decentralized applications (DApps), making these platforms more accessible and user-friendly. Optimism thus plays a crucial role in expanding the practicality and reach of Ethereum's blockchain technology.

Optimism is led by the Optimism Foundation, which is dedicated to growing the Optimism ecosystem. The foundation is completely funded by donations and grants and pledges to produce infrastructure that promotes the growth and sustainability of public goods. The foundation has set several milestones for the development of Optimism, including the introduction of Optimistic Rollup, the launch of the EVM Compatible Testnet, and the opening of the Mainnet. The foundation is working on decentralizing the sequencer and implementing next-generation fault proofing. The initial token supply of Optimism was 4,294,967,296 OP tokens, with a token generation rate of 2% per year.