Microsoft is building Cortana into Windows 10, this is nothing new and we broke that news during the summer, but up until now, no screenshots had been leaked of the personal digital assistant.
Posted below is the first shot of Cortana in Windows 10 and we need to point out that this is an older version of the feature. In fact, the newer builds have an updated version that looks different than what you see here as it has more modern UI and the background is a different color too.
So what can Cortana do on the desktop? Well, it's pretty much the same as Windows Phone but this should not be a surprise. You can add items to a calendar and when an event is scheduled for that day, it will show up in Cortana just like on Windows Phone.
You can also search maps and get traffic just like you can on Windows Phone. One aspect that is somewhat unique to the desktop is that if you call someone using Cortana, it will open Skype and dial the contact; this assumes the contact is already in your address book.
While this is an older build of the feature and a lot has changed and will continue to change before the release, this is the first and best look we have so far. Although, we suspect that a lot more about Cortana will leak in the near future.