Optimism (OP) is a layer-two platform on Ethereum that improves dApp scalability and accessibility using "optimistic rollups". OP allows dApps to offload computation and data storage to a separate layer, enabling low-cost, near-instantaneous Ethereum transactions. It was introduced in 2019 and has been used to develop financial apps, social networks, games, etc. The team behind Optimism is made up of blockchain developers and researchers, including Ethan Frey and James Ray, and is funded by venture capital firms and individual investors.