Mintlayer

Mintlayer is a layer-2 sidechain solution built on top of the Bitcoin (BTC) blockchain. Mintlayer is led by Enrico Rubboli (a former senior engineer at Bitfinex, who also led the development of Tether/USDT), it launched its testnet on November 10th 2021, and is set to launch its mainnet in Q1 2022.

In short, Mintlayer enables the creation of tokens and smart contracts "powered by" (inheriting the security of, and providing interoperability with) Bitcoin. This makes DeFi use cases such as those currently found on Ethereum and other blockchains possible and scalable in a truly "Bitcoin native" environment (using real Bitcoin, not pegged or wrapped) for the first time. Mintlayer also supports Access-Control-Lists which facilitate the creation of compliant stock/security tokens, coinjoin-like features (transaction batching and signature aggregation), Lightning Network, NFTs, a new tokenization standard for issuing Monero-like tokens with confidential transactions, and the first ever free market for gas currencies (i.e. you can pay for transaction fees using any token that has been issued on Mintlayer, as long as there is demand from block signers).