Apple working on OS X 10.10
Apple announced OS X 10.9 Mavericks earlier this year at the Worldwide Developers Conference 2013.
A Golden Master (GM) version of the new operating system was released to developers and some users last week. GM indicates that this code is ready for release.
Although no release date has been announced for OS X 10.9 Mavericks, most speculation seems to be pointing to the week of 21 October.
There have been no indications that Apple is planning to change its practice of selling OS X upgrades exclusively through the Mac App Store at $20.99.
10.9 marks a change from the 'big cat' naming convention used internally or publicly for (Mac) OS X since version 10.0 Cheetah. From 10.9, some Californian place names are being used - Mavericks is a surf spot on the San Francisco peninsula, bordering the north-west of Apple's Cupertino headquarters..
According to various reports, the coming OS X 10.10's user interface will continue to move in the direction of Apple's mobile devices, and with a look that will pick up elements from iOS 7 and the recently-facelifted iCloud.
But Apple does have a habit of introducing new technologies when it updates its Mac OS. Examples include App Nap in 10.9 (used to reduce the demands made on the system by hidden applications that are not doing useful work) and Power Nap in 10.8 (so Mail and certain other applications can stay up to date while the system is sleeping).