Windows Phone 8.1 will add Halo's Cortana to the mobile phone operating system.
Cortana, the artificial intelligence who became Master Chief's constant companion across the Halo series, serves as the equivalent of iOS' Siri personal assistant. Powered by Bing, Cortana will replace previous versions' "Search" function.
The new digital assistant can respond to natural user speech to set reminders, read text messages, conduct searches, place calls via phone line or Skype, and more, Microsoft said at a media event. With user permission, it can extend its services into third-party apps.
Cortana appears as a pulsing circle instead of a holographic woman on Windows Phone, but is still voiced by veteran Halo voice actor Jen Taylor.
Corporate VP of operating systems group Joe Belfiore introduced the virtual personal assistant, asking her whether she likes her name and her appearance, to which the circular "AI" replied that she resembles, among other things, "a halo."
Belfiore joked that Cortana "won't give away the answer to the storyline of the next Halo game."
Windows Phone 8.1 will also add a new Action Center to keep users aware of their phone's current status and a customizable Start screen.