Well, after months of being offered as an experimental feature and being the cause for many 1-star reviews for incompatible apps on the Play Store, ART (Android Runtime) is finally on its way to becoming the default runtime on Google’s mobile OS. The latest changes to the Android Open Source Project (AOSP) indicate that the next version of Android will do away with Dalvik and replace it with ART as the one and only Android runtime.
For those unaware, Dalvik is the runtime that has been used on Android since its inception. Whenever an app is launched, Dalvik uses Just-in-Time compilation to compile the app’s bytecode in real-time, which is seen visually in the blank screen that shows up just before some apps are launched. ART, on the other hand, pre-compiles bytecode right when an app is installed, removing the need for the compilation to occur when the app is launched, thereby reducing app load times. This also indirectly affects battery life in some cases, as the processor doesn’t have to compile bytecode at each run of an app, which means you get slightly better battery life, though the effect is not always noticeable in real-life usage.
Now that ART is the default in AOSP, it shouldn’t be long before it makes its way to stock Android, and then to manufacturer versions of the OS. App compatibility will likely be an issue in the early days, but given how quickly many developers have supported ART even in its experimental stage (not to mention ART is probably being used by less than 10 percent of all Android users, as KitKat itself is only on around 14 percent of devices), it shouldn’t be an issue for long once the next version of Android comes along.