- General website compatibilityEarlier today, Apple seeded Mavericks 10.9.3 Build 13D17 to employees along with a new iTunes 11.1.6 beta that restores local contact and calendar syncing to developers, but the Mavericks beta should be seeded to developers in the near future.
- Safari Push Notifications
- Login AutoFill
- Credit Card AutoFill (OS X Mavericks only)
- Extension Compatibility
Previewed at WWDC, launching in the fall.