If the new OS X follows the same pattern as last year's Yosemite there will be the opportunity for members of the public to sign up to be part of the beta testing scheme, and a lucky few will be able to download a version of the beta later in the summer (in 2014 the beta was released to public testers on 24 July).
The final release of OS X 10.11 isn't likely to come until October, based on the past few years. Yosemite launched on 16 October 2014 at the same time as Apple announced new iPad, the Retina iMac and an updated Mac mini. That said, OS X could launch a month earlier, alongside iOS 9. It would make a lot of sense if the two operating systems were launched at the same time as many features rely on the other operating system to work - such as Yosemite's flagship Continuity features. If the new operating systems are even more unified it would be a shame if Apple makes the public wait a month to take advantage of half the features.
How much will OS X 10.11 cost?
When Apple launched Mavericks it surprised everyone by making it free. Yosemite was also free, so we think it's a safe bet to presume that the next version of OS X will also be free.
OS X 10.11 System requirements
It seems likely that the system requirements will be the same as OS X 10.9 Mavericks and OS X 10.10 Yosemite. For those systems users required 2GB of RAM, 8GB of available storage, and needed OS X 10.6.8 (Snow Leopard) or later. You need Snow Leopard because without that you won't have access to the Mac App Store, which you need to download the new version. Luckily Apple still sells DVDs of Snow Leopard for this purpose - find out how to get one here: How to get Snow Leopard.
As for which Macs will be supported, OS X 10.9 and OS X 10.10 were able to run on the following Mac models, dating back to mid-2007:
iMac (Mid-2007 or later)
MacBook (13-inch Aluminium, Late 2008), (13-inch, Early 2009 or later)
MacBook Pro (13-inch, Mid-2009 or later), (15-inch, Mid/Late 2007 or later), (17-inch, Late 2007 or later)
MacBook Air (Late 2008 or later)
Mac Mini (Early 2009 or later)
Mac Pro (Early 2008 or later)
Xserve (Early 2009)
While these Macs were classed as supported, they didn't support every new feature of Yosemite. There were a number of the Continuity features, which enabled better communication between iPhone, iPad and Mac, that didn't work on older Macs due to lacking newer Bluetooth support. There is a workaround though, read about how to get Continuity features such as HandOff and AirDrop working on an older Mac.
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