OS X Mavericks is the 10th version, This new version is not revolutionary as previous versions of OS X have been. It brings online several new features that before  Mavericks, was only on iOS. The keyboard changes that make your Mac will operate more efficiently and  the key new features and functions that bring benefits and unification of applications and processes to many Mac users.

Timer Coalescing

Timer coalescing is a computer system energy system technique that reduces central proccesing units (CPU) power consumption 

App Nap 
App Nap essentially puts apps that are not actively visible on your screen into a lower power consumption mode which saves you CPU cycles which in turns saves you battery. 

Ibooks
One of the new edition to OS X Mavericks that is a direct from iOS is iBooks. Giving you the ability to see your iBooks library, download items that you have sync’ed with iCloud and of course connect you to the iTunes store to purchase new books. 

Safari:
Has been completely redesigned and is far more intuitive as is the new Sidebar which allows you to see your bookmarks, reading list and new shared links from your contacts via Twitter. iCloud Keychain can also store your personal information and credit card information for easier and faster purchasing.

Maps:
 Maps are included in the platform and allows for directionssomewhere and send them to an iPhone for instructions once you are on the way, plus see Flyover mode, where the user can explorecities in 3D animation.

Iphoto: 
This app has an improved interface for exploring the albums also can move the photos around the iOS device screen to create newcomposite images.

Iwork: 
All these applications as well as the new Pages, Numbers and Keynote iWork, now are free and included with the purchase of anyMac or iOS device 

The changes Apple has made are for the better, though, and since it’s free, there’s no reason not to take advantage of all that great new stuff. The Mac operating system is designed to be easy to use and engineered to take full advantage of the technologies built into every computer we make.

The amount of downloads of OS X Mavericks has beating records. Compared to the last version of OS apple's downloads have increased from 1.6% to 5.5%. This huge incresed hints how popular and easy it is this new version. Moreover, the free version on iWork has given a new change in the technology are due to the fact that now you do not need to pay in order to create your own documents, movies...