We are proudly powered by AzerothCore an open source emulation project.
Interested how emulation works here is a link to the public source https://github.com/azerothcore/azerothcore-wotlk.
We merge changes to our blizz like realm also submit bugs and updates as needed.
Our battle realm is also powered by the same core but we use custom scripting and data.
The battle realm is closed source atm but if you have question on scripting feel free to ask in our discord channel.