Blockstream launched the Liquid Network sidechain fairly recently.[0] The features that distinguish it from the Bitcoin main chain are fast settlement times (1-minute blocks), confidential transactions (versus BTC's transparent txs), and the ability to issue unique assets such as tokenized fiat, crypto assets, and other pretty exciting digitized assets.

[0] https://blockstream.com/liquid/

Disclosure: I work at Blockstream.

Thanks, I’ve missed that development.