OS X Mavericks

OS X 10.9 "Mavericks" is the tenth major release of Mac OS X. It was announced at June 10, 2013, at WWDC 2013. The RTM was released on October 22, 2013 and it boasts several changes over the original OS X releases.

System Requirements
OS X Mavericks can run on most Macs that can run OS X Mountain Lion; as with Mountain Lion, 2 GB of RAM, 8 GB of available storage, and OS X 10.6.8 (Snow Leopard) or later are required. Mavericks is free to upgrade and all later versions are free.

The full list of compatible models:


 * iMac (Intel-based)#Aluminum iMac|iMac]] (Mid-2007 or later)
 * MacBook (13-inch Aluminum, Late 2008), (13-inch Polycarbonate, Early 2009 or later)
 * MacBook Pro (13-inch, Mid-2009 or later), (15-inch or 17-inch, Mid/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)

Changes
Mavericks made Apple history for two distinct reasons: 1) For the first time, OS X was released to all qualifying Mac users free of charge as a system upgrade on the Mac App Store, and 2) Mavericks is the first release that stopped using feline codenames and switched to California-based titles, thus making it the start of a new generation or line of OS X. Mavericks also did not change system requirements significantly (if at all) from Mountain Lion.

While aestetically the same as 10.8 "Mountain Lion" (the previous release), 10.9 introduced memory compression, improved paging, and new energy management features, along with Time Coalescing. Also, OS X Mavericks is the first version of OS X to boot with checking kernel extension signatures, denying load to kernel extensions that are not properly signed.