Apple has released new versions of its OS X desktop operating system every year as of late. You know what that means? It will more than likely release another version sometime in the next few months, and we might even get our first sneak peek at the 2014 Worldwide Developers Conference.

UPDATE: If you're looking for our coverage of OS X Yosemite, you can find all the details here.

Apple announced OS X Mavericks - the tenth major release of OS X - at WWDC 2013, bringing enhancements to Mac's battery life, Finder, iCloud integration, and more. The software also marked the beginning of yet another change in naming conventions: Apple moved from names of big cats to names of locations in California.

Apple could continue with names of locations for the next version of OS X. Just before WWDC begins a banner has appeared at Moscone West for WWDC 2014, according to several tweets. The banner has an image of what looks like California's Yosemite National Park in the background with an X in the foreground.

We've gathered all the speculation and everything you need to know, below.

READ: Apple in 2014: Pocket-lint predicts

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What is Mac OS X 10.10 Yosemite?

Prior to OS X versions, Apple labeled its Mac OS versions as 1, 2, 3, 4, 5, etc, until it reach 10 and switch to the Roman numeral for 10 in 2010. Apple then released updated versions of OS X labeled with cat-related names like OS X 10.0 Cheetah and OS X 10.1 Puma. In 2013, Apple broke tradition again by launching OS X 10.9 Mavericks.

Word is this version will be called OS X 10.10 Yosemite.

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When will Mac OS X 10.10 release?

In recent years, Apple has released updated versions of OS X annually. Apple announced OS X 10.8 Mountain Lion in February 2012, followed by a public roll-out in July 2012. The company then announced OS X 10.9 Mavericks in June 2013 before making it available to the public in October 2013.

Looking at this pattern, Apple will likely unveil the next OS at its Worldwide Developer Conference later tonight. But keep in mind that Apple isn't consistent with its unveil and release dates. So, even if the next OS does unveil in summertime, there's no guarantee you'll have it installed by autumn.

READ: WWDC 2014 rumours: What to expect at Apple's conference in June

Will Apple make Mac OS X 10.10 free?

Apple released OS X 10.9 Mavericks as a free upgrade. There's no reason to suggest it won't do the same for the next Mac OS. However, if the company does slap a price tag on the software, just remember that OS X Mountain Lion cost £13.99 when it launched for the public.

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What features will Mac OS X 10.10 have?

Nothing's confirmed, but several reports have claimed to know what Apple is planning for its next Mac OS. Here's a look at the most persistent rumours:

OS X 10.10: Siri

More than two years ago, Apple introduced its voice assistant technology on the iPhone 4S and iPad. Apple was then expected to implement Siri on the Mac in OS X 10.9, but that never happened. In fact, it is still absent on the Mac. However, new rumours indicate OS X 10.10 may finally support Siri.

OS X 10.10: AirDrop (between Mac and iPhone and iPad)

Apple's AirDrop technology, which debited on Mountain Lion, allows you to drop files between Macs on the same network. AirDrop then arrived for iOS devices with the release of iOS 7 last autumn.

While that sounds nice and dandy, Apple neglected to make AirDrop compatible between Mac and iOS devices. The ability to drop a file from your iPhone to iMac would be a much appreciated feature, and it is rumoured to come as a feature in OS X 10.10.

OS X 10.10: iOS 7-like design

When Apple gave iOS a makeover with iOS 7, it wowed us all by introducing transparent elements and flat aesthetics and getting rid of oudated skeuomorphism. Mac OS X still hasn't adopted these design changes, but under the leadership of Apple's designer Jony Ive, there's a good indication the next Mac OS will look very iOS 7.

Tech website 9to5Mac claimed Ive is leading a "significant" design overhaul for OS X, and that the new design will be a "cornerstone new feature". Unfortunately, the website couldn't give more specific details other than noting the design would include white textures. It also noted the mockups online are not accurate.

OS X 10.10: Control Centre

And lastly, some speculation has wondered if the Notification Centre on Mac OS X will add the Control Centre that debuted with iOS 7. Like most of these rumours though, nothing has been confirmed by Apple.

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Mac OS X 10.10 concepts

Designer Danny Giebe recently published some concepts of a flat version of Yosemite (some are above). They're all strictly from his imagination but still worth looking through if you like to wonder about all the possibilities too.