## **Overview** [Optimism](https://www.optimism.io/) is a Layer-2 scaling network for Ethereum that operates under a four-pillar design philosophy of [simplicity](https://docs.optimism.io/stack/protocol/design-principles#simplicity), [pragmatism](https://docs.optimism.io/stack/protocol/design-principles#pragmatism), [sustainability](https://docs.optimism.io/stack/protocol/design-principles#sustainability), and [optimism](https://docs.optimism.io/stack/protocol/design-principles#optimism). Optimism [aims](https://help.optimism.io/hc/en-us/articles/4411894310427-Why-use-Optimism-) to increase Ethereum’s transaction throughput while decreasing the cost of transacting on the network. This is achieved through [Optimistic Rollups](https://docs.optimism.io/stack/protocol/overview), which [allow](https://help.optimism.io/hc/en-us/articles/4413163242779-What-is-a-rollup-) transactions to be executed on [OP Mainnet](https://twitter.com/optimismFND/status/1672281032962478080), Optimism’s blockchain, while relying on Ethereum for settlement, consensus, and data availability. When Optimism users sign a transaction and pay the associated [gas fee](https://docs.optimism.io/stack/transactions/fees) in ETH, the pending transaction is stored in a [private mempool](https://docs.optimism.io/chain/differences#mempool-rules) before being [executed](https://docs.optimism.io/stack/protocol/overview#block-execution) by the sequencer. Blocks of executed transactions on OP Mainnet are [created](https://docs.optimism.io/stack/protocol/overview#block-production) every two seconds and periodically [batch-submitted](https://github.com/ethereum-optimism/specs/blob/d119b4e937185c0b44ceb910bd2559f6fd36d7df/specs/protocol/derivation.md?plain=1#L193) as transaction call data to Ethereum by the [sequencer](https://etherscan.io/address/0x6887246668a3b87F54DeB3b94Ba47a6f63F32985). Optimism’s namesake originates from the fact that transactions are optimistically assumed to be valid. ## **History** **Optimism’s Beginnings** Plasma Group was [founded](https://medium.com/plasma-group/deployplasma-dd1cf0b2ab55) in January 2019 as a non-profit [researching](https://twitter.com/optimismFND/status/1516439487588364291) Ethereum scalability. Based on a commercially reasonable search, no information regarding who founded Plasma Group has been disclosed. In June 2019, Plasma Group integrated [concepts](https://ethresear.ch/t/on-chain-scaling-to-potentially-500-tx-sec-through-mass-tx-validation/3477) from Vitalik Buterin’s rollup design into its [own](https://plasma.build/t/rollup-plasma-for-mass-exits-complex-disputes/90). This led to the project team’s [ideation](https://medium.com/plasma-group/ethereum-smart-contracts-in-l2-optimistic-rollup-2c1cef2ec537) of an Optimistic Rollup. In January 2020, Plasma Group [recapped](https://medium.com/plasma-group/on-to-new-beginnings-e9d76b170752) its year of research before sunsetting Plasma Group and [introducing](https://medium.com/ethereum-optimism/optimism-cd9bea61a3ee) the Optimism Public Benefit Corporation (Optimism PBC), created by its founders [Benjamin Jones](https://www.linkedin.com/in/benjamin-jones-381943107/), [Karl Floersch](https://www.linkedin.com/in/karlfloersch/), [Jing Wang](https://twitter.com/jinglejamOP), and [Kevin Ho](https://www.linkedin.com/in/kevinjho/). **Road from Testnet to Public Mainnet** In February 2020, the alpha release of the Optimistic Virtual Machine (OVM) was [announced](https://medium.com/ethereum-optimism/optimistic-virtual-machine-alpha-cdf51f5d49e), and its code was open-sourced. The [OVM](https://medium.com/ethereum-optimism/ovm-deep-dive-a300d1085f52) is an Ethereum Virtual Machine (EVM) compatible execution environment that was the first implementation of a Layer-2 optimistic rollup network. In September 2020, Optimism [launched](https://medium.com/ethereum-optimism/light-at-the-end-of-the-tunnel-c390a05bbcb8) a phased testnet of its envisioned scaling solution. In January 2021, Optimism [recapped](https://medium.com/ethereum-optimism/optimism-year-in-review-6624dbba266c) its first year before soft launching its [mainnet](https://medium.com/ethereum-optimism/mainnet-soft-launch-7cacc0143cd5) in a similar tiered approach that featured several centralized [defense layers](https://medium.com/ethereum-optimism/mainnet-soft-launch-7cacc0143cd5#:\~:text=Of%20course%2C%20the,and%20new%20features.) to protect early users. The public mainnet was eventually [delayed](https://medium.com/ethereum-optimism/optimistically-cautious-767a898f90c8) in March 2021 to allow for “a more coordinated community launch.” In July 2021, Optimism [announced](https://medium.com/ethereum-optimism/retroactive-public-goods-funding-33c9b7d00f0c) its [Retroactive Public Goods Funding](https://app.optimism.io/retropgf) (RetroPGF) program and RetroPGF 1 was [held](https://medium.com/ethereum-optimism/retropgf-experiment-1-1-million-dollars-for-public-goods-f7e455cbdca) in October 2021. Optimism expanded its mainnet by [opening](https://medium.com/ethereum-optimism/community-launch-7c9a2a9d3e84) applications to the OVM beta in August 2021. This process began the whitelisting of projects to launch in coordination with the project team. In preparation for the public mainnet launch, September 2021 saw Optimism [unveil](https://medium.com/ethereum-optimism/the-future-of-optimistic-ethereum-7f22d987331) an upgrade to replace the network’s OVM and EVM compatibility with “[EVM equivalence](https://medium.com/ethereum-optimism/introducing-evm-equivalence-5c2021deb306).” This upgrade enabled projects to “one-click deploy” EVM protocols on Optimism while they run [near-identically](https://docs.optimism.io/chain/differences) as on Ethereum. Finally, on Dec. 16, 2021, Optimism [announced](https://medium.com/ethereum-optimism/all-gas-no-brakes-8b0f32afd466) the public mainnet was officially launched after the project team removed whitelist requirements. As a result, anyone could deploy smart contracts on [Optimism](https://medium.com/ethereum-optimism/to-optimism-4f01cc0eaa10). **Governance, Incentive, and Technological Developments** After Optimism’s public mainnet launch, the following network developments took place: - Throughout February and March 2022, Optimism reduced gas fees by [lowering](https://medium.com/ethereum-optimism/fancy-numbers-how-we-lowered-fees-for-optimism-users-a3bb80cbc65f) its variable rollup cost and [batch-compressing](https://medium.com/ethereum-optimism/the-road-to-sub-dollar-transactions-part-2-compression-edition-6bb2890e3e92) call data. - In March 2022, Optimism [introduced](https://medium.com/ethereum-optimism/cannon-cannon-cannon-introducing-cannon-4ce0d9245a03) the idea for a fault proof called “[Cannon](https://github.com/ethereum-optimism/optimistic-specs/wiki/Cannon-High-Level-Overview).” - In April 2022, Optimism [recapped](https://optimism.mirror.xyz/Fdpds7l4yE2VDpLN4AZQUCjpBYdoPrIHw6a4uzUepmw) its history and declared a new chapter “driven by community ownership and governance.” Later that month, Optimism [introduced](https://optimism.mirror.xyz/gQWKlrDqHzdKPsB1iUnI-cVN3v0NvsWnazK7ajlt1fI) the [Optimism Collective](https://app.optimism.io/announcement), announced the OP token alongside Airdrop 1, and rebranded “Optimism PBC” to “OP Labs PBC.” Additionally, [Optimism Foundation](https://community.optimism.io/docs/governance/what-is-the-optimism-foundation/) was founded to steward the Optimism Collective. - In May 2022, Optimism announced the “[OP Stimpack](https://optimism.mirror.xyz/ND1czJOoJYyUQrnFtRmEYDiAiSvnvXqyq58ANJc2Nig),” where OP tokens were distributed as an incentive from the Governance Fund via a “[Phase 0](https://community.optimism.io/docs/governance/gov-fund/#phase-0)” distribution to 24 projects. - In May 2022, [Airdrop 1](https://community.optimism.io/docs/governance/airdrop-1/) went [live](https://optimism.mirror.xyz/qvd0WfuLKnePm1Gxb9dpGchPf5uDz5NSMEFdgirDS4c), distributing OP tokens to 248,699 wallet addresses based on various [eligibility criteria](https://community.optimism.io/docs/governance/airdrop-1/#airdrop-1-allocations) and [overlap bonuses](https://community.optimism.io/docs/governance/airdrop-1/#overlap-bonus). - In May 2022, Optimism [announced](https://blog.oplabs.co/introducing-optimism-bedrock/) the development of its “Bedrock” upgrade, which aimed to [reduce](https://blog.oplabs.co/heres-how-bedrock-will-bring-significantly-lower-fees-to-optimism-mainnet/) gas fees through [batch compression](https://community.optimism.io/docs/developers/bedrock/?ref=blog.oplabs.co#batches), [shortening](https://community.optimism.io/docs/developers/bedrock/?ref=blog.oplabs.co#shorter-deposit-times) Ethereum to Optimism deposit times, [increasing](https://blog.oplabs.co/two-step-withdrawals/) bridge security, [enabling](https://community.optimism.io/docs/developers/bedrock/?ref=blog.oplabs.co#improved-proof-modularity) fault proofs and validity proofs, [improving](https://community.optimism.io/docs/developers/bedrock/?ref=blog.oplabs.co#improved-node-performance) node performance, and further [equalizing](https://community.optimism.io/docs/developers/bedrock/?ref=blog.oplabs.co#improved-ethereum-equivalence) Optimism and Ethereum. - In October 2022, Optimism [introduced](https://optimism.mirror.xyz/fLk5UGjZDiXFuvQh6R_HscMQuuY9ABYNF7PI76-qJYs) the [OP Stack](https://docs.optimism.io/stack/components), and the vision for a “Superchain” emerged. The OP Stack is Optimism's modular, open-source, forkable technology stack that allows for the creation of interoperable Layer-2 blockchains (”OP Chains”). - In December 2022, Optimism [announced](https://optimism.mirror.xyz/wqk1Yeyn2OhV9paDzbRXvQ0m0JYDu2npbSkMClwk1rY) RetroPGF 2, where OP tokens would be [distributed](https://community.optimism.io/docs/governance/retropgf-2/#) to projects in the tooling and utilities, infrastructure and dependencies, and education categories. - In February 2023, [Airdrop 2](https://community.optimism.io/docs/governance/airdrop-2/) went [live](https://optimism.mirror.xyz/lPZEkFF7LU2ZlrO-dsV3p_LtWQUaknFGfxFMgSz3vGA), distributing OP tokens to 307,965 wallet addresses based on various [eligibility criteria](https://community.optimism.io/docs/governance/airdrop-2/#airdrop-2-allocations) and [bonus attributes](https://community.optimism.io/docs/governance/airdrop-2/#bonus-attributes). **Superchain Era** In 2023, Optimism’s vision for a “Superchain” was brought to life: - In February 2023, Optimism formally [announced](https://optimism.mirror.xyz/2jk3D1Y8-hid8YOCUUa6yXmsyzNCYYyFJP0Nhaey9x0) its vision for a “[Superchain](https://app.optimism.io/superchain),” a [network](https://docs.optimism.io/stack/explainer#the-superchain-at-a-glance) of [OP Chains](https://docs.optimism.io/builders/chain-operators/overview) built with the [OP Stack](https://docs.optimism.io/stack/components). A technical explainer of the OP Stack can be seen [here](https://stack.optimism.io/docs/understand/explainer/). - On the same day, Coinbase [announced](https://www.coinbase.com/blog/introducing-base) and [launched](https://base.mirror.xyz/jjQnUq_UNTQOk7psnGBFOsShi7FlrRp8xevQUipG_Gk) the testnet for [Base](https://base.org/), the first OP Chain. - In June 2023, Optimism’s [Bedrock upgrade](https://www.notion.so/Bedrock-Mission-Control-EXTERNAL-fca344b1f799447cb1bcf3aae62157c5?pvs=21) went [live](https://twitter.com/optimismFND/status/1666850591669202965). The upgrade drastically [reduced](https://twitter.com/OPLabsPBC/status/1674823796572798996) gas fees for users and developers. It [modularized](https://blog.oplabs.co/op-stack-modular-scalability-for-l2s/) Optimism, allowing developers to use the OP Stack to [launch](https://console.optimism.io/) custom OP Chains. Lastly, Bedrock [introduced](https://twitter.com/OPLabsPBC/status/1674823814159515662) a consistent two-second block time and enabled [support for EIP-1559](https://docs.optimism.io/builders/chain-operators/management/configuration#eip-1559-gas-algorithm), introducing a [priority fee](https://docs.optimism.io/builders/app-developers/transactions/parameters#selecting-the-priority-fee) on Optimism. - With the launch of Bedrock and the upcoming launches of OP Chains, the previously lone blockchain called “Optimism” was [rebranded](https://twitter.com/optimismFND/status/1672281032962478080) to “OP Mainnet” to delineate “between the OP Mainnet blockchain and the Collective, vibe, and ethos that “Optimism” encompasses.” - In June 2023, Optimism [announced](https://optimism.mirror.xyz/oVnEz7LrfeOTC7H6xCXb5dMZ8Rc4dSkD2KfgG5W9cCw) RetroPGF 3, where OP tokens would be [distributed](https://community.optimism.io/docs/governance/retropgf-3/) to projects working on the OP Stack, collective governance, the developer ecosystem, and/or end user experience and adoption. - In July 2023, Optimism [announced](https://optimism.mirror.xyz/JfVOJ1Ng2l5H6JbIAtfOcYBKa4i9DyRTUJUuOqDpjIs) a draft of the “[Law of Chains](https://gov.optimism.io/t/law-of-chains-v0-1-full-draft/6514),” an open-neutrality framework to guide governance decisions and promote user protection, decentralization, and economic autonomy across the Superchain. The purpose of these standards is to reduce the fragmentation of Optimism by unifying the [network](https://docs.optimism.io/stack/explainer#the-superchain-at-a-glance) of [OP Chains](https://docs.optimism.io/builders/chain-operators/overview) that opt into the Law of Chains. - In August 2023, Optimism’s most active OP Chain, [Base](https://base.org/), [launched](https://base.mirror.xyz/KPrKIukePtM2Iz945_3GpQJ-tgMf1hoato5isStLXJI) on mainnet. - In September 2023, [Airdrop 3](https://community.optimism.io/docs/governance/airdrop-3/) went live, distributing OP tokens to 31,529 wallet addresses that [delegated](https://community.optimism.io/docs/governance/howto-delegate/#app) OP tokens. - In January 2024, Optimism’s [Canyon upgrade](https://docs.optimism.io/builders/node-operators/network-upgrades/canyon) was [approved](https://vote.optimism.io/proposals/20327152654308054166942093105443920402082671769027198649343468266910325783863) and went [live](https://twitter.com/OPLabsPBC/status/1745912787409285369). The upgrade [included](https://blog.oplabs.co/canyon-hardfork/#:\~:text=to%20Canyon%20passes.-,Scope%20of%20upgrade,-The%20Canyon%20upgrade) various EIPs meant to “reduce how quickly the base fee rises when blocks are over the gas target,” enable developers to have access to a commonly used contract on all OP Chain networks, and fixed a bug where “the deposit transaction nonce was not in consensus encoding.” - In February 2024, [Airdrop 4](https://community.optimism.io/docs/governance/airdrop-4/) went [live](https://optimism.mirror.xyz/3tkU-Y5479JPw83I6jp7GTu_0_q-TWEKAXckm3XKl28), distributing OP tokens to 22,998 wallet addresses that [created](https://community.optimism.io/docs/governance/airdrop-4/#airdrop-4-allocations) successful non-fungible token (NFT) mints across Ethereum, OP Mainnet, Base, and Zora. - In February 2024, Optimism’s [Delta upgrade](https://docs.optimism.io/builders/node-operators/network-upgrades/canyon) was [approved](https://vote.optimism.io/proposals/64861580915106728278960188313654044018229192803489945934331754023009986585740) and went [live](https://twitter.com/OPLabsPBC/status/1760795773665493432), [introducing](https://blog.oplabs.co/span-batches/) Span Batches that reduced costs across [OP Chains](https://mode.mirror.xyz/O6Q8JbL6Dn8v0d6EnqPzKgy2ZqcQ6JSxb3jLebc4mPI?ref=blog.oplabs.co). - In March 2024, Optimism’s [Ecotone upgrade](https://docs.optimism.io/builders/node-operators/network-upgrades/canyon) was [approved](https://vote.optimism.io/proposals/95119698597711750186734377984697814101707190887694311194110013874163880701970) and went [live](https://twitter.com/OPLabsPBC/status/1767969403872715169), introducing [EIP-4844 blobs](https://blog.oplabs.co/the-collective-triumph-of-4844/) for data availability after Ethereum’s Dencun upgrade. The upgrade resulted in a [\~90.00% reduction](https://twitter.com/Optimism/status/1774942033607872658) in transaction fees on OP Mainnet. - In March 2024, Optimism announced the winners of its [We \[Heart\] The Art](https://optimism.mirror.xyz/K6b7_LpAK88jWo0FJLRGflxxpIzbgVJdYfGZ3pFcfUM) creator contest, which ran for several months and [distributed](https://optimism.mirror.xyz/I6g_dbBkZXxCiKNS0lp0Zul-qhzjtnbvjHTv5y6B_dU) OP tokens to 47 creators. - In March 2024, Optimism released an updated [roadmap](https://optimism.mirror.xyz/nz5II2tucf3k8tJ76O6HWwvidLB6TLQXszmMnlnhxWU) for RetroPGF. Four rounds of RetroPGF are planned for the year. Each round will have a specific focus, and for the first time, funding will [extend](https://optimism.mirror.xyz/nz5II2tucf3k8tJ76O6HWwvidLB6TLQXszmMnlnhxWU#:\~:text=Who%20is%20eligible,and%20Retro%20Funding.) outside of OP Mainnet and into various [OP Chains](https://console.optimism.io/). - In April 2024, Optimism [announced](https://twitter.com/Optimism/status/1780986610823413909) RetroPGF 4, where OP tokens would be [distributed](https://gov.optimism.io/t/retro-funding-4-onchain-builders-round-details/7988) to “Onchain Builders” that are “building across the Superchain, increasing demand for blockspace, and driving value to the Collective.” Applications will open on May 23, 2024. OP Mainnet is operational and many OP Chains like [Base](https://www.base.org/), [Zora Network](https://zora.co/), [Mode Network](https://www.mode.network/), [Fraxtal](https://www.frax.com/), and [Redstone](https://optimism.mirror.xyz/cFewllyj7WcfZXUreo3mGct0PDRHDjxm8lCSAWPHhvk) are a part of the Superchain. A full list of OP Chains can be seen [here](https://github.com/ethereum-optimism/superchain-registry/tree/main/superchain/configs/mainnet?ref=blog.oplabs.co). A live OP Mainnet status is viewable [here](https://status.optimism.io/), while onchain statistics can be seen on [Dune](https://dune.com/optimismfnd/Optimism-Overview). Furthermore, OP continues to serve as the governance and incentive token for Optimism, while the Optimism Collective guides the network's future through the [ability](https://github.com/ethereum-optimism/OPerating-manual/blob/main/manual.md) to propose and vote on [proposals](https://github.com/ethereum-optimism/OPerating-manual/blob/main/manual.md#valid-proposal-types) related to areas such as network upgrades and OP incentive distributions. Planned features to [decentralize Optimism](https://blog.oplabs.co/endgame-is-stage-2/) include a [Fault Proof System](https://docs.optimism.io/stack/protocol/fault-proofs/overview), [zero-knowledge proofs](https://optimism.mirror.xyz/XS7Ko4sn5Wab0dEWsXie7wO5JhFj5v7G1ckggfoY87U), a [decentralized sequencer](https://docs.optimism.io/chain/security/faq#sequencer-decentralization) set, [decentralizing control](https://blog.oplabs.co/progressing-towards-decentralization-highlights-from-the-keys-in-mordor-summit/) of upgrade keys, and [reducing](https://optimism.mirror.xyz/PLrAQgE1EGRo7GRrFoztplFChnUZda4DFGW3dkQayxY) governance power held by the Optimism Foundation.