The latest version of OS X has been announced and will launched later in the year.
The release - dubbed OS X Mavericks and numbered 10.9 - brings more than 200 new features over and above those inOS X 10.8 Mountain Lion. As with Mountain Lion, there's further integration with the company's mobile operating system iOS.
Explaining the thinking behind the name, Apple's Senior Vice President of Software Engineering Craig Federighi joked that the company had ran out of cat-related names, and decided to turn to "our backyard", Apple's home state of California, for its next round of names.
The third version of the Developer Preview of the new OS has now been made available to those in Apple's OS X Developer programme, meaning that launch can't be too far away. It contains bug fixes rather than anything else
Mavericks isn't a huge leap forward in terms of features, but it sees Apple tweaking and introducing content related apps and services such as Maps and Notifications synchronizing across all Apple devices and iBooks now coming to OS X. Also going are the irritating and outdated interface elements such as leather/paper-style backgrounds.

OS X 10.9 release date

Speaking at WWDC 2013, Federighi confirmed that Mavericks will be available in Autumn. That confirms our prior prediction. Expect the new OS to be with us in September. The web is awash with information on how devs can install Mavericks from a USB stick - so without borking your main OS X install.

OS X Mavericks price

Previous releases of OS X have been low priced and Mountain Lion was even cheaper at GBP £14, USD $20, AUD $21. We're expecting the OS X 10.9 price to be similar.

OS X 10.9 multi-monitor support

The previous major release of OS X, Mountain Lion, was largely a hit, boosting the system's feature set and security. More than three million people downloaded the OS during its first four days on sale.
However, it also mangled some iOS features into the mix that didn't work terribly well, such as iCloud documents, and a sub-standard full-screen mode, which Apple looks to have fixed by baking multi-monitor support into Mavericks.
The update now makes the dock and menu bar follow the user on whatever screen they're working on, and each display can be shown independently. The new OS has also added the ability for desktop activity to be wirelessly beamed to a HDTV via an Apple TV box and Airplay.

OS X 10.9 performance

Apple claims the latest version of OS X has made several tweaks under the hood to improve performance the energy efficiency and responsiveness of Macs. This includes grouping together "low-level operations", which the company says allows the CPU to spend more time in a low-power state.
This has been twinned with two new features, the first being "App Nap", which reduces the power consumed by apps that aren't in use. The second, "Compressed Memory", makes Mavericks automatically compress inactive data until it's needed again, at which point it's instantly uncompressed.

OS X Mavericks Finder

Other features making an appearance in the latest version of OS X include the Mac OS 9-style Finder Tabs. This positions a plus symbol to the top right of Finder that allows new tabs to be opened or dragged into other positions, with similar behaviour to a web browser. Users can customise views for individual tabs, move files between tabs, and run the Finder with multiple tabs open in full-screen.
Tags have also made an appearance in Maverick, which appear in the Finder Sidebar to enable users to view files by project or category. They can be added to files or folders within Finder or iCloud to simplify locating documents.

OS X Safari

Apple has also made several tweaks to Safari, claiming that the browser has smoother scrolling, is nippier than before, and outperforms its rivals in energy efficiency, memory efficiency and JavaScript performance. It now uses what Apple describes as a "new process-per tab architecture", which it claims makes Safari more responsive, stable and secure.
Another new feature dubbed iCloud keychain stores login information, Wifi password, and credit card details within Safari for users' convenience when making purchases online
Additionally, the browser now houses a new quick launch screen with a column for bookmarks, which can be reordered using drag and drop. It has also received a hefty dollop of social love in the form of "shared links", which collects URLs posted by Twitter and LinkedIn contacts to display them in a single stream in Safari's sidebar.

iOS X Mavericks Maps and iBooks

Two apps from iOS, Maps and iBooks, have made their way to Mavericks. Maps includes features such as interactive flyover data, vector graphics, and 3D views. It also provides the ability to send map coordinates to iPhones with a button push for voice navigation on the move.
Maps now integrates with OS X's Calendar app too, giving users the ability to look up travel times between two locations to prevent them from scheduling anything in that period. Users don't have to go directly to the Maps app for such navigational wizardry either, as Apple has integrated maps into Mail, Contacts and Calendar. Developers can do the same with their own apps using the Map Kit API.
Meanwhile, Apple has brought iBooks and its 1.8 million titles to the desktop, including any books users have previously purchased. The company gave an interactive demonstration of iBooks' new features at WWDC, which include zooming in, changing font sizes, and adding annotations. Seamless integration across iPhones and iPads means users can pick up books where they left off too.

OS X Mavericks notifications

Notifications were a welcome addition when they were introduced in Mountain Lion last year. This year, they have been beefed up with advanced capabilities that let users do anything from replying to messages or answering FaceTime calls from directly within the notification.
Handily, Apple has also made it so that iOS notifications sync with OS X, meaning users can check alerts sent to a Mac or mobile device, and vice versa.
Curious to know what we wanted to see in OS X 10.9 before today's event? Read on for our wishlist that we first posted earlier this year.

1. iBooks and Newsstand for OS X

OS X Mountain Lion was largely about bringing relevant features from iOS to the Mac, but Apple should go further. It's bizarre that both of Apple's major iOS apps for reading are not available on the Mac.
With OS X 10.9, Apple should release both iBooks and Newsstand for OS X, enabling you to read your favourite books and magazines on any Apple device, rather than restricting them to the iPad, iPhone and iPod touch.

OS X 10.9: what we want to see
You can buy books in iTunes for OS X, but you can't read them on your Mac. Bonkers!

2. Siri for OS X

Although Siri's not quite the revolutionary feature that was once promised, it nonetheless continues to improve. It's now finally useful outside of the USA, and once you've trained it to your voice, Siri can be used to rapidly speed up many tasks.
OS X already has plenty of built-in accessibility clout, and a number of different playback voices, and so it seems like a no-brainer to integrate Siri into the system.

3. Maps for OS X

When it first arrived on iOS, Apple Maps was rightly slammed, not least for its boneheaded assumptions when it came to directions. But the service continues to improve and is great for turn-by-turn.
On the Mac, it would be less useful, but we'd nonetheless like to see it, not least for researching and planning routes and journeys that could subsequently (along with favourite places) seamlessly sync to your iOS devices via iCloud.

OS X 10.9: what we want to see
Maps might not be perfect, but we'd like to see it on OS X

4. A more usable Contacts app

People bang on about skeuomorphism in OS X, and also confuse it with texture-oriented graphic design, which isn't really the same thing. In many cases, these approaches also happen to be a matter of taste (Calendar's leather, for example), but in Contacts, Apple's created a usability disaster.
Half-way house between digital book and app, Contacts is just a mess. We hope whatever Jonathan Ive brings to the OS X 10.9 party in terms of human interface leadership, it includes a firm emphasis on usability and not merely a hankering for minimalism. (More attention to detail regarding bugs would also be nice — Game Center remains an ugly, unusable, broken mess on OS X and needs some serious help.)

OS X 10.9: what we want to see
Every time we open Contacts, we wonder if we were very bad in a million previous lives

5. An enhanced Finder

Finder remains a straightforward way to get at your files, and recent updates have improved inline previews. However, we'd still like to see changes. For power users, the addition of tabs would be great to cut down on clutter; and for everyone, an emphasis on speed and performance would be welcome.
Spotlight could also do with a kick up the bottom speed-wise, which would improve Finder window searches, the standalone Spotlight menu and any app it's integrated into (such as Mail).

6. A broken-up iTunes

On iOS, iTunes is just a shop. Individual apps take care of other things: Music and Videos for media playback, App Store for buying apps, Podcasts for playing podcasts, and so on.
The mess that is iTunes for OS X could benefit from a similar approach, although with the app also having to exist for Windows, we doubt this is a wish on our list that Apple will ever fulfil.

7. Better window management

Window management on Mac OS and OS X has always been weak and Windows zoomed past with Aero Snap and related features. Third-party utilities exist on OS X for managing windows, but Apple appears hostile towards them.
Really, it should enable you to more easily and rapidly place windows side-by-side and in other common layouts, rather than making you move/drag/move/drag like it's 1984.

OS X 10.9: what we want to see
We love Moom. But OS X should have basic window management built-in

8. Improved iCloud document management

Apple's iCloud still seems very much like a work-in-progress, with the company feeling its way regarding what the system can do. In terms of document management, it's great for people working on their own and who produce relatively few files.
For anyone else, it's problematic at best - OS X 10.9 really needs to improve filing, sharing and collaboration regarding this aspect of iCloud.

OS X 10.9: what we want to see
Collaboration? Filing? Pah! iCloud does not care for such trifling matters!

9. Interface improvements

It's possible to argue all day about the direction in which Apple's interface should head, but two major widespread problems are apparent that really need fixing. First, Apple's infatuation with desaturation needs to end - people use colour to navigate and spot things, and that's now a problem in some apps (notably Finder and iPhoto sidebars).
Secondly, the company must address scalability. What works on an iPad and just about works on a MacBook Air frequently looks ridiculous on an iMac, such as full-screen apps with acres of space, sickness-inducing animated transitions, and the Fisher-Price-style Launchpad.

10. More cross-device intelligence

Our final wish is that Apple's operating systems would be a little more intelligent when it comes to cross-device purchases. In some cases, Apple gets it right: buy a song and you can (optionally) have it sent to all your Apple kit; buy an app on your iPhone and it'll download in iTunes and be sent to your iPad.
Great. But why can't we browse the Mac App Store (which, after all, is simply a web browser wrapper) on an iPad, buy an app and have it waiting on a Mac the next time we use it? It's almost like Apple doesn't really want us using a Mac any more, once we're comfy with an iPad…