Before turning to the developer-specific announcements at the company’s Worldwide Developer Conference, Apple CEO Tim Cook and senior vice president of software engineering Craig Federighi rolled out the new desktop and mobile operating systems developers’ apps will soon run on: iOS 8 and OS X 10.10 “Yosemite.”

First came OS X 10.10. While Federighi joked that since moving on from big cat names to California locations, the team toyed with naming the next version of OS X “Oxnard,” “Rancho Cucamonga” and “Weed,” but ultimately they landed on “Yosemite.” The new Mac desktop operating system has a translucent design, with windows, sidebars and even the Dock sporting a flat, translucent look. “Yosemite” also comes with a Dark Mode to darken the desktop background and color scheme.

OS X 10.10 Yosemite

Beyond just the look, the biggest feature added is Continuity, which turns the Mac into a fully functional extension of the iPhone. With Continuity, the user can switch between OS X and iOS devices when writing an e-mail, sending a text or making a phone call, with all their actions synced between every device.

Federighi explained that even with the iPhone in another room, a user can make or receive a phone call on his or her desktop. He demonstrated by calling up new Apple employee and Beats by Dre cofounder Dr. Dre. The new “Yosemite” Handoff feature allows a user to start an e-mail or message on an iPhone and pick it up on the desktop or tablet with automatic sync.

OS X 10.10 Yosemite

The new OS also comes with a feature called Mail Drop, which allows users to send encrypted mail attachments of up to 5GB via iCloud, as well as a markup feature to draw, circle and write superimposed on e-mails and PDFs.

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Apple used the debut of “Yosemite” to trot out its competition for Dropbox, Google Drive, OneDrive and the like, called iCloud Drive. The new cloud storage platform syncs all files across Mac and iOS devices, and Federighi made a point of mentioning that it even works on Windows.

As for the iPhone
After “Yosemite,” the keynote turned to iOS 8. The next version of Apple’s mobile OS will have interactive notifications, allowing users to reply to a drop-down notification without leaving the app they’re currently in, integrating the same Hand-Off and iCloud Drive features as “Yosemite” to pick up writing a text or e-mail on a different device.

iOS 8 will also come with a redesigned keyboard governed by a new feature called QuickType, which spurns autocorrect in favor of predictive, content-sensitive personalized typing suggestions. According to Federighi, QuickType “learns how you type” to suggest writing style and word choice based on who you’re talking to or what app you’re in.

iOS 8

The other big enhancements in iOS 8 are related to group messaging. iOS 8 users will have the ability to name threads, add or remove individuals from conversations, or turn on a “Do Not Disturb” feature for specific threads to stop getting notifications about a particular text conversation. There is also a new “Tap to Talk” feature for speaking and sending a text, which goes hand-in-hand with enhancements to Siri that allows the virtual assistant to be addressable with a “Hey Siri” voice command à la Google Now.

iOS 8 and OS X “Yosemite” will both be released to the public for free this fall, but developers can sign up for a preview today.