Android 4.4 KitKat has brought several changes to Google's mobile OS, but one mysterious addition is drawing significant attention. Tucked inside the developer menu is a new runtime option: Android Runtime (ART). Looking over the limited documentation on the feature doesn't give away much, but a report from Android Police has some interesting details.

To understand what ART may do, we need to discuss how things work now. At the heart of Android is the Dalvik runtime, which uses a just-in-time compiler to translate bytecode into instructions that can be run on the available hardware.

According to Android Police, ART takes a different approach to compilation, and it's an approach that could have serious performance and battery life advantages. ART will take the same software packages from the Google Play store and compile them during the installation process. The operating system then simply runs the ART-compiled software as it's stored. Not having to waste compute cycles on compiling bytecode every time you open an app should generate some improvements to responsiveness and battery life.

ART might offer a performance gain in other ways, too. Dalvik's strength was that the code it generated could be run on all types of hardware, an important factor when you consider the number of platforms that run Android. Dalvik's weakness was that the code wasn't necessarily optimized for that hardware. By compiling the software at installation, ART may be able to focus more on optimizing the code generated rather than simply generating code as quickly as possible.

It's possible that the runtime's presence is simply a proof of concept, testing the consistency with which ART-compiled software performs as expected without optimizing the code any further. And it's important to remember that all of this remains speculation until Google decides to share more information about its plans for ART.