Steam News announces the release of StarDrive 2 for Windows, OS X, and Linux. There are more details about Zero Sum Games' strategy sequel in their Steam Community announcement:

Greetings space fans! StarDrive 2 is now released! I know you'll be digging in to building your first space empire today, and it can be hard to step away when you've got the option for just, one, more, turn. But when you take a break, come say hi to us on the forums!

If you have some questions about how to play or you want to discuss strategy and tactics, then our experts will be on hand to help out. Also if you experience any technical issues, please come by the forums and we'll do what we can to resolve your issue.

Also don't forget to check out the Workshop! We've already got some modders adding ships and more to the game, so give that a gander to see if there's something for you there.