Apple today seeded build 13E25 of OS X 10.9.4 to developers, just under a week after seeding the third OS X 10.9.4 beta, build 13E19, and more than a month after the public release of OS X 10.9.3, which included enhanced support for 4K displays and syncing improvements.
It remains unclear what improvements the 10.9.4 update will bring to Mavericks, but it is likely to include bug fixes and stability enhancements. Apple is asking developers to focus on Graphics Drivers, Bluetooth, Audio Drivers, Finder, App Store, and Safari.
Article Link: Apple Seeds OS X Mavericks 10.9.4 Build 13E25 to Developers