Apple's next Mac operating system could be an exciting one, with rumours that the new OS X - whether it's called OS X 10.10 or OS X 11, or maybe even OS 11 without the X - will have a flatter, more minimalist design like iOS 7.

This article was updated 9 April 2014 with claims that Apple's design guru Jonathan Ive is overseeing the OS X 10.10 project, plus with news that Apple will hold WWDC on 2 June 2014 we expect to see a full preview of OS X 10.10 at that event.

Read more: What to expect from Apple at WWDC 2014

Here in our Mac OS X 10.10 release date, rumours and leaked images article, we'll keep you up to date with all the latest speculation about Apple's next operating system for Mac, so you'll know when it's going to come out and the new features it might have. Plus, we bring you all of the latest leaked images, mockups and concept illustrations of OS X 10.10 so you can see what it might look like.

Apple released OS X 10.9 Mavericks in October of 2013, after previewing it several months before at the Worldwide Developers Conference in June. Just days after its launch, OS X 10.10 was spotted in web analytics reports, suggesting that Apple is already hard at work on the next version of the software - we expect that Apple will preview features in the new version of OS X at WWDC in June 2014, but here's what we know about it so far.

Rumours have been hotting up and new concept images have sparked the imagination about what Apple could have up its sleeve... Read on to find out more.

OS X 10.10 launch date

Looking back over the past three versions of OS X suggests that a new version is likely to arrive in 2014.

In 2010, Apple announced OS X 10.7 Lion in October before releasing it to the public in July 2011. In February 2012, OS X 10.8 Mountain was announced before being rolled out in July 2012. Most recently, Apple announced OS X 10.9 Mavericks in June 2013 before making it available to the public in October 2013.

So, while Apple hasn't been consistent in its release dates, it has released a new Mac operating system every consecutive year since 2011.

It's difficult to predict a precise launch date as there has been no evidence to suggest a particular month or date yet, but we have heard that Apple is testing a new OS X, so it does seem that a 2014 release is on the cards.

With June's WWDC rapidly approaching, it's possibly that Apple will use that event as a platform to launch the new Mac OS, so the unveiling could be a matter of months away. Indeed, we expect that Apple will preview the next version of OS X at WWDC in June. It's even feasible that the new operating system could be ready for download soon after the keynote on 2 June.

However, with OS X Mavericks not launching until October 2013, it is seems likely that Apple will not update it's operating system until the autumn.

Apple OS X 10.10: new design rumours

Apple's senior vide president of design Jonathan Ive is said to be heading up the redesign of Mac OS X in the run up to the launch of OS 10.10 (codename Syrah).

A 9to5 report claims that Ive is leading a "significant" redesign and is focusing on aesthetic improvements.

With Jony Ive's expanded design leadership reaching the software side of Apple, we certainly expected to see his influence prominently in the next Mac OS X.

Apple OS X 10.10 - will it be like iOS?

One of the biggest rumours is that OS X 10.10 will take a lot of cues from iOS 7, but a comment from Apple's Phil Schiller has cast doubt over that theory. "We don't waste time thinking, 'But should it be one [interface]? How do you make these [operating systems] merge together?' What a waste of energy that would be," Schiller told Macworld, our sister title from the US in an interview in January.

Apple's head of software, Craig Federighi, added: "The reason OS X has a different interface than iOS isn't because one came after the other or because this one's old and this one's new. Instead, it's because using a mouse and keyboard just isn't the same as tapping with your finger."

Of course, that doesn't mean the next Mac operating system won't borrow some visual elements from iOS 7, adopting the more minimalist design that arrived on iPad, iPhone and iPod touch in September. However, it does make it clear that Apple is still treating the two operating systems as completely separate entities.

It's important to note that Apple has not officially released any information about its next Mac operating system, but we've been keeping an eye on reports from around the web for hints, speculation and evidence that could give us clues to what Apple is working on for OS X 10.10, and have analysed Apple's history for further insight.

What will Apple's next Mac OS be called?

The name of the next Mac OS isn't obvious this time. Prior to the OS X versions, the classic Mac OS versions were labeled version 1, 2, 3, 4, 5 and so on. In 2001, Apple reached version 10, which is when OS X was born, with the X being the Roman numeral for 10.

From then on, Apple has issued new versions of OS X labeled 10.x. So it began with OS X 10.0 Cheetah, followed by OS X 10.1 Puma and so on, until reaching OS X 10.9 Mavericks in 2013.

Reports that say that the next version of OS X has been spotted in web analytics refer to OS X 10.10, so we assume that's the number showing up in the analytics. (Mathematically speaking, of course, OS X 10.10 is technically the same as OS X 10.1, but software version numbers don't obey that rule.)

Which leads to the conclusion that it's possible that Apple may go to OS X 11. But would the 'X' make sense here? Will Apple decide to go to OS 11, or perhaps OS XI?

For the purpose of this article, we're going for OS X 10.10, but we'd love to know what you think Apple might decide to do with the name. Let us know in the comments section below or on Twitter.

As for the code name, we assume that Apple will continue with its new Californian theme. After running out of big cats following the launch of Mountain Lion, Apple went for Mavericks, a surfing location in California.

It's believed that the current internal codename for the next OS X is 'Syrah', a type of wine, though the internal codename isn't normally the one used for the public release (Mavericks was codenamed 'Cab' according to a screenshot from 9To5Mac.)

How much will Mac OS X 10.10 cost?

Apple surprised us this year by making OS X 10.9 Mavericks available for free. 

We expect Apple to continue to make OS X free in the future, like it does with iOS. Previously, OS X Mountain Lion was just £13.99, though, so even if Apple does decide to put a price tag on the next version, it shouldn't break the bank.

What new features will Mac OS X 10.10 have?

While there's no concrete evidence about the new features expected in the next OS X, taking a look back at some features missing from Mavericks gives us some clues as to what's yet to come.

OS X 10.10: Siri for the Mac

Many expected Apple to make Siri available on the Mac in OS X 10.9. Apple's voice technology was introduced more than two years ago on the iPhone 4S, and then on the iPad, but has yet to make its way onto the Mac. Perhaps OS X 10.10 will be the first operating system to support the voice-activated assistant.

Fresh reports as of early April suggest that Apple is planning to add Siri to the next version of OS X. The operating system already has dictation integration, which is one aspect of Siri's voice recognition abilities.

OS X 10.10: AirDrop between Mac and iPhone, iPad

AirDrop has been on the Mac since Mountain Lion, and means users can drop files between nearby Macs. With iOS 7, iOS devices got the AirDrop feature too. But unfortunately, Mac and iOS devices cannot AirDrop between each other. We'd love to be able to drop a file from our iPhone to iMac, so we're keeping our fingers crossed for this feature in OS X 10.10.

Reports from early April suggest that AirDrop compatibility with iOS should come with the next version of OS X.

OS X 10.10: Control Centre

OS X Mavericks has a Notification Centre, so perhaps Apple will decide to bring iOS 7's Control Centre to OS X 10.10.

OS X 10.10: iOS 7-esque design

iOS had a complete makeover with iOS 7, adopting transparent elements and ditching skeuomorphism. Mac OS X has yet to take on the new look, but it's quite possible that it will have a redesign that takes cues from the minimalist style of iOS 7 under the leadership of Apple's designer Jony Ive.

OS X 10.10 mockups, concepts and leaked images

While there are no leaked images of OS X 10.10, we have seen some really gorgeous iOS 7-esque concepts imagining what the future could hold for the Mac operating system.

In March, an OS X 10.10 concept design created by Danny Giebe emerged online, as shown below.

Giebe has introduced elements of transparency reminiscent of iOS 7, and altered the app icons to match iOS 7 too.

Designer Andrew Ambrosino created the below Mac OS X concept, which we particularly like.

A third Mac OS X 10.10 concept design we like is by Edgar Rios, who has also based his design on iOS 7.

See more of Edgar's designs on Behance.

We'll update this article as soon as we find out more about OS X 10.10, so check back regularly for new information.