Arbitrum

Arbitrum One opened to the public on August 31, 2021 as an optimistic rollup. Its original Classic stack proved demand but was not the final architecture. On the same date in 2022, One migrated to Nitro, which combined a Geth-based execution environment, ArbOS and a dispute machine designed to reproduce execution for fraud proofs.

The migration matters because ARB did not fund the early network or buy access to it. Users paid ETH for execution before the token existed and still do. ARB entered later as a way to direct selected protocol and treasury decisions, not as the fuel that makes Nitro run.

One and Nova share Nitro but make different data-availability promises. One posts rollup data to Ethereum. Nova's AnyTrust mode lets a Data Availability Committee certify off-chain availability in the normal case, reducing cost while adding a committee assumption. Calling both 'Arbitrum' should not conceal that trade.

Orbit extended the stack from two DAO-governed chains into a framework for dedicated chains. A builder can select a parent chain, data layer, gas token, governance and validation model. The Arbitrum Expansion Program attaches different economics depending on the parent, but it does not make every Orbit chain an operational branch of the DAO. Its chain owner and contracts must be inspected on their own terms.

One and Nova normally accept transactions through a sequencer. It chooses a fast order, compresses transactions and posts batches to Ethereum's Inbox. Nitro also exposes a delayed Inbox so a user can route a transaction through L1 and obtain eventual force inclusion. That escape hatch limits censorship, but it does not remove the sequencer's influence over short-term ordering.

Validation is a different job. Validators assert L2 state and challenge conflicting assertions on Ethereum. BoLD activated in February 2025 to bound the challenge process and remove the permissioned validator gate on One. Nova was upgraded too, yet the Foundation's 2025 report says its validator allowlist remained and was expanded. BoLD also preserves a final grace window in which the Security Council can intervene, so permissionless participation is not the absence of emergency authority.

The Foundation says service providers run both sequencers under its mandate and that residual revenue goes to the DAO treasury after costs. Public rules explain the relationship, but the reviewed materials do not provide one durable registry of every current operator endpoint and human keyholder. That operational layer deserves live verification rather than inference from ARB ownership.

ARB launched on March 23, 2023 with 10 billion units: 42.78% for the DAO treasury, 26.94% for the team and advisers, 17.53% for investors, 11.62% for individual users and 1.13% for ecosystem DAOs. Team and investor allocations are subject to four-year lockups: the first unlocks came after one year, followed by monthly unlocks across the remaining three years. The airdrop broadened voters; it did not erase concentrated scheduled supply.

ARB uses delegated voting power. A wallet may hold tokens without casting that weight until it delegates. The token has representations on Ethereum, One and Nova, while the official governance overview says One tracks total supply. Its contract also contradicts the shorthand 'fixed at 10 billion': the owner may mint up to 2% of current supply once every 365 days. This is a ceiling on an authorized mint, not a promise that minting will occur.

The first omnibus proposal asked voters to ratify a 750 million ARB administrative budget for the Foundation. It failed after the Foundation had already received or used 50 million. The sequence made the new DAO confront whether a vote was authorizing a transfer or acknowledging a decision already taken.

AIP-1.1 rewrote the arrangement. It placed the remaining 700 million ARB in a four-year continuous linear lockup, capped release at 175 million per year and added transparency reporting, while 3.527 billion remained under direct DAO treasury control. The episode did not dissolve the Foundation; it forced the allocation, vesting and reporting boundary into explicit governance terms.

Today the Core Governor routes constitutional changes and upgrades, while the Treasury Governor routes spending. Both count delegated voting power, apply quorum rules and pass actions through timelocks. A token vote is therefore an instruction moving through a system, not a direct contract-admin key.

The L1 Upgrade Executor owns critical One and Nova contracts on Ethereum, while chain-specific executors control parameters on the L2s. Governance timelocks are the ordinary authorized callers. The Security Council is the exceptional path: the official overview describes 9-of-12 multisignatures able to call upgrade executors, cancel proposals and bypass the DAO schedule when required.

The Arbitrum Foundation is a Cayman Islands foundation company, not another name for all ARB holders. Its bylaws make it serve the ecosystem and allow token governance to elect or remove directors through the AIP process, but directors may reject an approved AIP if carrying it out would violate fiduciary duties, governing documents, law, contracts or the Foundation's interests. That limit applies where Foundation action is needed; it is not a general power to rewrite every on-chain vote.

The resulting system is neither a single corporate switch nor pure token rule. ARB delegates steer governors and treasury, the Foundation commissions operations, validators contest state, executors hold upgrade authority, and the Council protects an emergency lane. Security depends on watching the handoffs among them.