FTG Station(FreeTG Station) is station, that will be always licensed under GPL v3. It means, you don't need to open your code to people, that connecting to your server, but you should open it to people, that has a dmb. Based on old TG station code before commit 333c566b88108de218d882840e61928a9b759d8f on 2014/31/12 at 4:38 PM PST
The main purpose of FTG Station is to be a platform for a good closed source builds. Many people creating a very good projects, based on SS13, but they all will be forced to open their code, because of AGPL. In my opinion, free code is a code that you can use as you like, you can share it with others or keep it closed.