updated 10:32 am EDT, Mon April 29, 2013
New OS expected to be evolutionary upgrade
The next major upgrade of OS X, v10.9, will concentrate on "power-user" features while bringing in more concepts from iOS, say sources for 9to5Mac. In the former category, several improvements to Finder are expected, such as tagging and tabbed browsing. Fullscreen apps should finally remain open on secondary monitors, and Safari is expected to get a new version with a new backend, improving performance and efficiency.
In general v10.9 is forecast to be an evolutionary step, not making any major interface changes. One possibility is the Mac debut of Siri, but one source claims that recent executive shakeups have shifted around multiple OS X and iOS projects, so Siri may or may not still be in the works even though it was in early v10.9 builds. Also uncertain is whether or not Siri will be in every version of v10.9 or tied to new Mac hardware.
Apple has allegedly been testing a new multitasking scheme for OS X similar to the app switcher in iOS, which would be functional for apps running in the background, one source says. Another possible carryover is iOS' app-pausing technology, which pauses unnecessary processes so that memory and processing power can be dedicated to active and/or essential ones. It's uncertain, however, if the feature will be included in the final v10.9 release.
It's lastly claimed that Apple is working on a major upgrade of its Xcode development suite, v5.0, for sometime later this year. The software is reportedly getting a redesign, including new app testing tools.
Apple has promised to show off OS X 10.9 at WWDC 2013. 9to5's sources say that the OS is currently codenamed "Cabernet," but at WWDC the company should announce a different name, in keeping with the big-cat theme every edition of OS X has used so far.