Google introduced ART in Android 4.4, and let the developer do testing and other stuff on ART. Today, Google has just pushed changes to the master branch of AOSP that remove the aging Dalvik virtual machine and replace it with ART.
It’s been a long way coming, but ART is finally taking the reins from the venerable Dalvik as Android’s default virtual machine. Standing for Android Runtime, ART was introduced in Android 4.4 KitKat as an experimental feature that users could activate from Developer Options. At the time, Google made it clear that ART was still a work in progress and that issues with various apps were to be expected.
One of biggest differences between ART and Dalvik is that ART pre-compiles bytecode when the app is installed, unlike Dalvik, which requires Just-in-Time compilation, which happens when an app is launched. Through Ahead-of-Time compilation, ART cuts down app launch time in half, according to Google, though users are not likely to notice a huge effect on performance. The two changes were made by Google senior software engineer Brian Carlstrom to the master branch of AOSP.
The first commit removes Dalvik components from the project, while the second switches to the new Android Runtime.
