Good question. I do not know. You can check the busy.org code or contact with them about how did they designed the website. busy.org is essentially another website that works like steemit.com but with a different design.

Steem developers team may publish an easier way to create other websites that interact with the API soon. Steemit.com is receiving DDOS attacks so making the creation of other websites easier is one of their priorities at the moment.