Halo has been Microsoft's most recognizable video game franchise since Bungie's Halo: Combat Evolved launched alongside the original Xbox in November 2001. It's so ingrained in the tech giant's brand that the AI character Cortana serves as Microsoft's real-world virtual assistant, up against Apple's Siri and Amazon's Alexa. Even after Bungie moved on to start the Destiny series, Microsoft continues producing Halo games with its Xbox Game Studio 343 Industries.