Arbitrum launches the first L3 XAI to challenge Optimism, initiating a vertical revolution.

2023-09-04 15:36

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The launch of XAI holds significant strategic importance for Arbitrum, as it represents a positive declaration of war against OP.

Original Title: "Arbitrum's Vertical L3 Revolution: XAI Declares War on Optimism"

Original Author: yyy

Focusing on the Rollup track, the epic battle between Arbitrum and Optimism is truly exciting. Optimism uses its OP Stack to expand horizontally, while Arbitrum takes a different approach with the Arbitrum Orbit to initiate a vertical L3 revolution. The Arbitrum team personally launched the first L3-XAI based on Arbitrum Orbit and officially declared war on Optimism.

In my opinion, the launch of XAI is of strategic importance to Arbitrum and is a positive declaration of war against OP. Leveraging its powerful B-side resources, OP has successively promoted Binance and Coinbase to build L2 chains based on its OP Stack, expanding the L2 ecosystem vigorously. At that time, Arbitrum seemed to be silent and did not show much action. With OP's rapid development, the swift launch of XAI does not seem to be a coincidence.

Arbitrum Orbit

Before talking about XAI, we have to talk about Arbitrum Orbit. Arbitrum Orbit is a universal modular L3 stack that allows developers to build dedicated L3 chains on top of it. Transactions on the L3 chain will be settled through Arbitrum L2 (Arbitrum One or Nova). XAI is a game-focused L3 chain built on top of Arbitrum Orbit.

Arbitrum Nova vs. XAI

Nova is a general-purpose L2 focused on gaming scenarios. In theory, it should already meet the needs of gaming scenarios, so why launch XAI? The reason is simple: compared to Nova's positioning as a gaming public chain, XAI, as a gaming-specific L3, can achieve higher performance and has dedicated computing and storage resources. This makes it possible to have resource-intensive use cases on the chain, such as computationally intensive AI models.

XAI benefits natively from Arbitrum's technology stack: Nitro+ BOLD+ Stylus. Nitro is an upgrade to One's technology stack. It directly compiles the core of Geth, which is a mainstream Ethereum client, through the basic layer of client software, thus achieving higher Ethereum compatibility. The difference between Arbitrum Nitro/One/Nova has been discussed separately before and will not be repeated here. (Related link)

BOLD

BOLD is a permissionless verification mechanism proposed by the Arbitrum team, with the aim of minimizing the delay in settlement status. In layman's terms, for optimistic rollups, there is generally a one-week challenge period, during which users have to wait one week to withdraw from L2 to L1; if validators discover any issues with the submitted L2 transactions during the challenge period, they can initiate a challenge.

There are two challenges here: 1) Who has the authority to issue challenges? 2) Why is it not open to everyone to issue challenges?

The current fraud-proof challenge mechanism is not permissionless and is carried out by specific roles acting as challengers. If the challenge is permissionless, malicious challengers can prevent the settlement status from being confirmed by continuously launching DDOS attacks.

For example, withdrawals are supposed to arrive within a week, but in reality it may take longer.

By introducing the BOLD mechanism, on the one hand, it can achieve permissionless verification, which is more in line with the decentralization concept of blockchain; on the other hand, it can minimize the delay of settlement status. BOLD allows a single honest validator to win against any number of opponents on Ethereum when in dispute, making DDOS attacks ineffective.

Stylus

Stylus is an open-source SDK developed by Arbitrum that supports building applications in multiple languages. This is a product that implements EVM+ compatibility. In short, developers can use traditional Solidity language as well as WASM-compatible languages such as Rust, C, and C++ to build applications on Arbitrum. Additionally, Stylus makes Dapps execution more efficient and significantly reduces gas costs.

Stylus is not limited to supporting Rust, C, and C++, but also supports Move, Sway, Cairo, and Go, among others. Imagine that in the future, dApps on Aptos/Fuel/StarkNet can be migrated to Arbitrum with just one click. It is even possible to achieve a one-click L3 chain upgrade through Arbitrum Orbit.

What's even more interesting is that BOLD and Stylus are both universal modular components;

Developers can natively integrate BOLD and Stylus into L3s launched on Arbitrum Orbit for specific use cases.

It is also possible to decide on the integration of the above modular components through decentralized DAO governance, after the smooth operation of L3 has been launched and established.

XAI has fired the first shot in the Arbitrum L2 defense battle, and the competition with Optimism may have just begun.