Aurora is on version 1.9.5 C#, available at the Aurora Forums.
Contact Erik on the forum for a wiki account.
Designer mode Ctrl+D lets you alter certain aspects of the game and is an extensions of SpaceMaster Mode.
All Designer Mode does is switch off the flag that makes NPR empires hidden. It can be useful for tracking down bugs that are being caused by NPRs. Designer Mode also allows you to modify NPRs. Unfortunately, if you change the wrong thing you can corrupt the game because you added something the NPRs AI can't handle or removed something it was relying on.
This may result in erroneous bug reports, caused by someone inadvertently corrupting the game, bugs the developer would not be able to replicate. Hence, it is password protected.