Apple previews Mac OS update, Mountain Lion NEW YORK (AP) - Apple is releasing a developer preview of an update for the Mac operating system, dubbed "Mountain Lion," that will copy more features and apps from the iPhone and iPad to the Mac. Apple says the new software will be on sale this summer, a year after it released the latest update, "Lion." Mountain Lion will include Game Center, an iPhone app which stores high game scores and helps users find opponents. It will be integrated with iCloud, the new Internet storage service designed for the mobile devices. The new Messages app, also copied from the mobile operating system, will replace iChat. Lion users can download a preview version of the app for free. A new Notification Center will show alerts from email and calendar programs, just like on the iPhone.