Apple will apparently add Siri to the Mac later this year when it releases its next major version of OS X which will be OS X 10.12.
Apple has apparently been testing out versions of its voice activated assistant for OS X internally and they are apparently ready to launch a version of the software later this year.
According to Mark Gurman from 9 to 5 Mac, Siri will be situated in the Mac Menu Bar in a similar way that Spotlight is and the software will also be voice activated.
Apple is expected to reveal OS X 10.12 at its Worldwide Developer Conference which is expected to take place in June, the software will probably land on the Mac some time in September or October.
Source 9 To 5 Mac
