If you're unfamiliar with Starjack, Limbo bills it as a "4X, real-time strategy, massively multiplayer game." What exactly is 4X? It stands for explore, expand, exploit, and exterminate, and you'll be able to do all these things in real-time (i.e., no turns) in a constantly changing persistent universe. Starjack is also unique in that nearly everything in the game is player-created, including ships, fleets, troops, colonies, and resources.
If it sounds like a lot to digest, don't worry, as Limbo assures us that the game is as accessible as it is deep. To that end, Starjack allows players to automate various empire management tasks, "removing the tedium and the need for micromanagement." You can learn more at the game's official website, where you can also create an account and grab the beta client.