StarCraft II's expansion pack, Heart of the Swarm, is already out in some parts of the world, and it's launching tomorrow in North America. To celebrate, let's take the opportunity to examine more than 20 years' worth of real-time strategy history in today's Show Us gallery, and see how much the genre has evolved…

Of all the studios Electronic Arts has bought over the decades, few were as talented or important to the history of video games as Westwood Studios.