At Apple's Worldwide Developers Conference, Tim Cook announced Mac OS 10.10 or "Yosemite," during the Keynote address on Monday. Surprisingly, Yosemite won out over OS X Weed, which apparently was popular among Apple's marketing team.
Apple's new look for OS X Yosemite, due this fall
The new version of OS X sports subtle window translucency for windows and the Dock, plus OS 7-style flat-looking icons -- a look Apple called "refined," and "fresh." Apple added a Dark Mode to the operating system for developers and designers, and carried the theme's look into applications, too. The company gave a little hat tip to coders and designers with a new Dark Mode view that changes many bright interface elements to darker colors, and improved font readability and consistency across apps and the OS.
OS X will be getting a more iPad-like Notification Center with a today view for easily checking your schedule and tasks. Notification Center also gained support for add-on widgets that let users customize exactly what information they see.
Spotlight will get a big visual overhaul that pulls the search field from the menu bar and places it center screen. Searches group together related results in a way Apple thinks will make more sense, and searches can include results from Bing, Wikipedia, Apple's online app and media stores, and more.
Yosemite will include new markup features in Mail that let users add annotations and signatures to messages, an updated interface for Safari with improved and more flexible privacy controls, and DuckDuckGo Web search support.
OS X Yosemite, as well as iOS 8 will sport a new feature called Continuity that lets users start activities on any Apple device, and then jump to another device and continue where they left off. The new version of Mac OS will also work as a speaker phone-like system for the iPhone with caller ID viewing, and the ability to answer and make calls from the desktop.
OS X Yosemite will be available as a free upgrade through the Mac App Store this fall, and as a public beta this summer.
[Updated with additional information about OS X Yosemite]