There are some similarities with Polkadot’s parachains, especially with the idea that these side chains can have their own logic and data structure that the main chain doesn’t need to know about. On Hathor Network, these side chains will be connected with the main DAG with special transactions that will live on the main network and also point to the side DAG. That way, the accumulated work (mining) done on the main network also secures these side networks, guaranteeing their safety
Hathor has a RFC with the basics idea, which is planned to expand on a research phase on this first semester of 2021: https://gitlab.com/HathorNetwork/rfcs/blob/side-dags/0000-side-dags.mdBut it’s important to note that Hathor doesn’t see that as incompatible with PolkaDot or a direct competitor. Hathor believes the crypto ecosystem can benefit from all of it and having these networks cooperate is the best solution. That’s why Hathor is starting an interoperability work group.