Rootstock (RSK) is a pegged Bitcoin sidechain. That means it is uses bitcoin as it's native currency, is merged-mined with Bitcoin and can have different features from Bitcoin mainchain. On of the cool features of RSK (there are many), is that it allows us to build smart contracts (secured by the Bitcoin hashpower).

Work started on RSK, I think 5 years ago, and at the time there was a lot of excitement about sidechains. I remember them being considered the future of Bitcoin, the next evolutionary step. I still think that's true.
However, building *secure* and *decentralised* sidechains for Bitcoin is REALLY hard. Most people have heard of Liquid which is a trusted federation and not censorship resistant and that has come to be viewed as what Bitcoin sidechains are, and so the excitement waned.

In the meantime, TSK has continued to slowly evolve and it is now, in my opinion, finally evolving to a state where Bitcoiners can start building decentralised alternatives to exchanges, lending platforms and derivatives markets for Bitcoin.

This is our goal with Sovryn. To build a decentralised, open economy around decentralised open money: Bitcoin. Call it Sovrynomics Wink

You can check out our (obviously) opensource code here: https://github.com/DistributedCollective/

If things keep going reasonably well, Sovryn will be ready to start facilitating margin trading, spot trading and lending for Bitcoin in about 6 weeks.