This is my list of favourite features of WWDC 2014.
OS X 10.10 Yosemite
I dislike the naming conventions Apple has taken on since Mavericks (10.9).
The new design has gone closer to the iOS 7 design. It has a more white and much less skeuomorphic design (although it will be much harder to get used to with Mac OS X because it's been the way it is at the moment for a lot longer than iOS had, although I'm sure you will agree Apple did this the right way around).
AirDrop from Mac OS X to iOS is perhaps the best feature. Mac OS X Lion introduced this feature but unfortunately, Apple did not include compatibility between Mac OS X and iOS in the latest versions. Now, we finally have this.
An improved Notification Center is coming to Mac OS X. This looks to be an on screen Notification Center at the moment, although I am not entirely sure.
Generally Yosemite brings more design features than core features at the moment.
One of the more core features being updated is iPhoto. Apple promises a newly designed iPhoto when 10.10 is released.
Apple's new child previously known only as 'Healthbook' to most is now known as 'Healthkit'. Healthkit is designed to keep an eye on your health and it has been discussed for month and months.
iOS will feature a Shazam-like feature integrated straight into the operating system. This is a feature Windows Phone users have through the use of Bing music, and one that I found very useful when I had a Windows Phone. It is a very welcome feature to iOS.
iOS developers can also develop widgets for the iOS Notification Center - something that has been required for sometime, but since the Control Center came along, demand has slowed for. None the less, this feature will be very useful for most.
Perhaps the most shocking change to the iOS operating system will be the ability to install custom keyboards! I still have not got over this, but developers will be able to build their own on screen keyboard and distribute it over the App Store. This is very unlike Apple, allowing a core part of the operating system to be changed.
Apple announced it's home system or smart home system that has been speculated for some time. Not much was revealed at the event however.
A new iTunes feature that is coming is being able to share your purchases with other people. So if you are part of a family you will be able to share any purchases with them. Up to six people can share the purchases. This is perhaps my favourite feature to come of the event.
The Swift programming language
Apple also announced their new programming language, which will come to XCode called Swift.