At its annual conference for developers, Apple today announced the next version of its desktop operating system, OS X. OS X 10.10 Yosemite follows in the footsteps of last year's OS X 10.9 Mavericks with an even cleaner design and more features inspired by iOS. This year, the theme is all about "continuity."

The flat design, translucent panels, and lack of gradients and textures of iOS 7 can be found throughout OS X 10.10, lending a much more modern look to the desktop operating system. App icons feature flatter designs, the dock and windows of apps have sharper corners, and a new system font is meant to improve overall readability. App windows can also adjust their color temperature based on a user's selected background, just like iOS. There is also a new, user-selectable "dark mode" that dims the entire interface for better focus while working. Apple's Craig Federighi calls it a focus on "clarity, but also utlity."

The Notification Center has been expanded with a new "Today" view for calendar, reminders, weather, and more, and Apple says that it can be extended even further with third-party app widgets. Apple's universal search tool, Spotlight, has been redesigned and improved with more functionality, including instant results for web searches.

One of the biggest changes is Apple's new iCloud Drive service, which integrates all files stored in a user's iCloud account into the Finder file browser. Users can browse their files stored in the cloud and organize them into folders and tag them like any other types of files. Apple says that all iCloud Drive files will sync across Mac computers and even Windows PCs. MailDrop is a new feature in Apple's Mail app that lets users attach large files to emails with their iCloud accounts, bypassing the attachment size restrictions many email services have. Mail has also gained the ability to edit attached images with simple text and arrow overlays.

Apple's Safari browser has undegone a significant revamp, with a cleaner design, less chrome, and better search integration. Safari's integrated share menu has been expanded with recent people you've messaged and RSS feeds, and there is a new tab view that shows thumbnails of all open tabs. Apple says that Safari now runs JavaScript code faster than any other browser on the market.

The theme of continuity in OS X is greatest seen in its new abilities to interact with an iOS device. AirDrop between OS X and iOS is finally supported, allowing users to transfer images and other data between their mobile devices and their desktop without using a cable. Users can seamlessly transfer the file they're working on in Pages on their Mac to an iPad or iPhone. OS X 10.10 using location awareness, so email messages that are composed on an iPhone can instantly be continued on a Mac. It's also now possible to start up a mobile hotspot directly from a Mac, without having to touch the iPhone.

Apple's iMessage service has been accessible across iOS and OS X devices for a number of years, but now the company is expanding it to include traditional text messages. Phone calls can similarly be relayed from an iPhone to a Mac, and a Mac can be used as a giant speakerphone. Calls can be intiated and dialled right from a Mac, as well.

Apple also says it plans to bring its Photo app from iOS to OS X early next year, but it did not go into detail as to how it relates to the existing iPhoto app.

Overall, OS X 10.10 Yosemite is more of a visual refresh than a complete overhaul of the operating system, much like iOS 7 was a refresh of iOS that didn't change how the system works in a significant way. The biggest improvement for OS X is the better integration and interaction with Apple's mobile devices, making it that much more beneficial for users to be completely bought in to Apple's entire ecosystem. But overall, it shouldn't be that jarring of a change for most users.

Apple says that developers will be able to access the new OS X 10.10 Yosemite starting today, and a public beta will be available this summer. The final public release will be this fall. As with last year's OS X 10.9, 10.10 Yosemite will be available as a free upgrade to existing users.