Cortana vs. Siri: Battle of the Virtual Assistants

With Windows Phone 8.1, Microsoft is taking on Siri, Apple's chatty assistant in the iPhone. In Microsoft's corner is Cortana, a brand-new virtual personality that shares the same name as Master Chief's holographic helper from the Halo games.

Cortana made her debut at Microsoft's Build conference earlier this month, but she's now in the hands of Windows Phone developers and should be coming to the first Windows Phone 8.1 handsets in a couple of weeks. Compared to Siri, which arrived in fall 2011 on board the iPhone 4S, Cortana is a newborn lamb.