As I mentioned earlier in a few comments, SteemWorld will be open source next year, but I need some time to prepare for that.

I added the following to my proposal post, so that no one will miss it:

Since quite some time already, I am in the process of preparing my code to be published on GitHub. As I want to deliver a clean and secure solution for the whole Steem community, it's hard to say exactly, when SteemWorld will be completely open source, but I am doing my best to get it done until Q2 2020.