The Vasari faction in Sins of a Solar Empire can research an ability called Returning Armada. This grants a new ability to the Phase Stabilizier tactical structure -- a sort of artificial phase lane jump gate that can link your systems. The new ability is also called Returning Armada, and it will summon five to eight frigates of various types every five minutes.
It doesn't seem like a lot, and it's a serious chore to research. The Phase Stabilizer isn't cheap, either. But the ships quickly gets ridiculous. If you have five planets each summoning the Returning Armada, you get new ships every minute. Double that, it's every thirty seconds, without cost to you.
I'm currently running a game as the Vasari. I'm playing against three random mediums, in 2v2 mode. I rushed straight for Returning Armada, and didn't do a thing to help my teammate, who actually turned on me! I wiped him off the map for his insolence. I then easily defeated one other opponent with my free ships, and now I'm simultaneously destroying a pirate base and the remaining opponent as well.
The bad thing about the Returning Armada is that you only get certain kinds of ships. There are no planetary bombadiers, so you're forced to scuttle some of the endless waves of light carriers or heavy cruisers that come your way. It's also a way to jump-start your economy, since by scuttling you gain additional resources that are reclaimed.
Returning Armada is a powerful ability but one difficult to pull off, especially in a free-for-all game -- or where your backstabbing teammate turns on you.