According to ChainCatcher, Rollkit, a modular framework product under Celestia, announced the launch of Bitcoin sovereign Rollup, using Bitcoin as the data availability layer.

Rollkit is a new framework developed by Celestia, launched on February 21, which aims to modularize the different components of the blockchain, enabling developers to deploy Rollup, customize and select the data availability layer as the source of blockchain data, and the execution layer for processing transactions. (Source link)