Astria

Astria is a shared sequencing network that allows many rollups to share a single decentralized network of sequencers.

In Astria's architecture, transactions are ordered and submitted to DA on Celestia. Their Astria EVM went live on Celestia's testnet (15-12-2023).

Testnet went live on 19-10-2023.

Proposed to become a sequencing layer to Aztec, with no response (4-2024). It's sequencing layer is modular (17-4-2024):

"The Sequencing Layer is modular, which means that it only focuses on sequencing. It does not execute rollup data, just orders it on behalf of participating rollups. The Sequencing Layer nodes use CometBFT to come to consensus on ordered blocks.

Multiple rollups can use the Astria Sequencing Layer for transaction ordering.

Because the Sequencer is ignorant of rollup state, many rollups can join the network without driving up the cost of sequencing and data availability (DA). Because the Sequencing Layer is agnostic to execution, rollup developers have ultimate freedom when it comes to choosing VMs, proving mechanisms, etc. expanding the design space for rollup/app development with Astria."