Whitepaper: https://docs.bitboost.org/

TL;DR
Bitboost proposes an EVM execution environment on Bitcoin. It uses Bitcoin as the sequencer and data availability layer for transactions and executes these transactions on an off-chain EVM indexer. It connects to Bitcoin through a PSBT-based decentralized trading pair between its native token and BTC. The entire protocol is trustless and has the same security level as Bitcoin.

It's a working project and please refer to the whitepaper for more details. If you have any questions about the project, please leave a comment and we will reply ASAP.