Microsoft Cortana released on April 2 2014, and which is developed by Microsoft. It is the licensed property of Microsoft.
In the Technical Preview of Windows 10, also some files leaked showing that Microsoft will port it to their new OS. Its name comes from Cortana, the artificial intelligence character in Microsoft's Halo video game series, with Jen Taylor, the character's voice actress, returning to voice the personal assistant's US-specific version. It is similar in function to Siri, which is found on Apple's iOS devices.