Layer 2 scaling solution Scroll, a new zero-knowledge Ethereum Virtual Machine (zkEVM) compatible protocol, has confirmed its Mainnet launch.

In a Tuesday update on X, the team behind the project said that the Scroll Mainnet was live, along with an accompanying blog post announcing the development.

Blockchain data from the Etherscan block explorer shows that Scroll’s smart contracts have actually been live since Oct. 8, meaning the team likely waited on making the launch public until this week. 

“After three successful testnets spanning over 15 months with extensive testing and rigorous security audits, we are thrilled to announce that Scroll Mainnet has officially launched for everyone to use,” wrote the Scroll team in the blog.

The security audits for Scroll’s bridge and rollup contracts were audited by OpenZeppelin and Zellic, while its zkEVM circuits were reviewed by Trail of Bits, Zellic, and KALOS.

Through its sequence of testnets, the team monitored over 450,000 smart contracts that were deployed and over 90 million total transactions. The team also plans to continue using Scroll Sepolia as a testing ground for all upgrades to the Mainnet.

Scroll joins a growing list of zkEVM scaling solutions that launched this year, including Polygon’s zkEVM and Matter Labs’ zkSync Era. The scaling solutions essentially provide lower transaction costs at higher throughput by batching transactions together off-chain.

Optimistic rollups, like those offered by Arbitrum and OP Labs, also offer similar functionality to scale Ethereum-based applications but differ from zk rollups in their inherent design.

For instance, optimistic rollups can run smart contracts on the main blockchain directly, while zk rollups are unable to do so. However, zk rollups don’t require cryptographic validity proofs and hence eliminate the waiting periods during which transaction validity may be challenged on an optimistic rollup.

Ethereum cofounder Vitalik Buterin said at an ETH Seoul event that he believes zk rollups will eventually surpass optimistic rollups for this reason, although he acknowledged that the zk technology is still more complicated to build.