Apple's new range of iPads has taken most of the headlines after yesterday's launch event. But arguably they weren't the biggest surprise, or the best news, of the day.
In a shock announcement Apple also said that Mac OS X 10.9 'Mavericks' - the new update to its venerable operating system for laptops and desktops - is now free.
And that's not just free to users of the previous version. Every Mac computer released since the 2009 Mac Mini will be eligible for the upgrade, via the Mac OS X App Store.
But why should you upgrade? What's different and what are the key new features?
Here's a great summary to let you know what's new in Mavericks.
9 Biggest Surprises From Apple's October 2013 Launch
iPad Mini With Retina Display(01 of07)
Open Image ModalThe new Mini is not a hugely surprising update in theory, but is an excellent one in person. It looks just as if someone has lifted a plastic sheet off the screen of the old version, allowing the new Retina display to shine with 2048 x 1536 pixels - the same as on the iPad Air.
iLife(02 of07)
Open Image ModalApple announced lots of new updates to its iLife suite of lifestyle apps, and its iWork productivity software. Our favourite? 'Drummer', a new addition to Garageband which looks set to make real drummers obsolete with dynamic, adjustable drumming which you can add to your demos. Neat.
iPad Air(03 of07)
Open Image ModalThe iPad Air is dramatically thinner, lighter and more powerful than the old model - but this is still the familiar iPad you know and (probably) love. It's boosted by the new A7 chip, has a much thinner bezel and is a decent upgrade all around.
Mac Pro(04 of07)
Open Image ModalThe Mac Pro desktop computer, announced back in June at WWDC, received pricing and availability information. The hugely powerful computer - which is aimed at graphics, video and IT professionals - will start at $2999 for a 3.7GHz, quad-core Xeon processor and 12GB DRAM. It's available in December. (credit:Getty Images)
Macbook Pro(05 of07)
Open Image ModalThe Macbook Pro has been upgraded, powered by the new Intel Haswell chips which offer huge improvements to battery life. The new 13-inch has a nine hour battery life and comes at a lower cost ($1499 in the US down to $1299). The 15-inch machine is powered by an Intel Crystalwell quad-core chip, with Iris Pro Graphics and up to eight hours of battery life, and also has a lower price than before (also down by $200). (credit:Getty Images)
App Store Numbers(06 of07)
Open Image ModalApple announced it has now sold more than 60 billion apps, from the more than 1,000,000 available on the iOS App Store. (credit:Getty Images)
OS X 'Mavericks'(07 of07)
Open Image Modal(Not the real packaging.) Mac OS X 10.9 Mavericks: the new update to Mac OS X for its desktops and laptops will be released for free, Apple said, for users who are running any version of the software. 'Mavericks', which adds features including revamped notifications, integrated Maps and much more, works for all Macs released since the 2009 Mac Mini - and is available immediately.