When Google launched Android 4.4 KitKat and the Nexus 5 along with it, their latest build of Android had an experimental switch many of us flicked; the ability to change runtimes on our devices. For a long time, apps on Android have used the Dalvik runtime, but in Android 4.4 something new was introduced; ART. Android Runtime as it has become known is a new way for Android apps to run on your device. The initial install of these apps take longer and they take up a little more space, due to the code required being stored on your device, rather than Dalvik's "just-in-time" method. Since last Fall, many devices running Android 4.4 now feature the ability to turn on ART in the Developer settings. Now though, it looks like the next version of Android is going to kick Dalvik to the kerb in favor of ART.
Over at th XDA Portal, it's reported that two significant Code Review changes clearly state that Dalvik is to die a swift death in the next version of Android. Code review changes 98553 and 98618 are pretty clear about Dalvik being replaced, with one a longer message with the "Dalvik is dead, long live Dalvik!" declaration and another, more serious change simply saying "Switch from core to core-libart". Many of us have been predicting such a change ever since ART hit the scene, it might not be that much faster, but it does seem to have a slight impact on improving battery life and is certainly more efficient.
What implications this will have for devices running versions of Android below 4.4 looking to download new apps from the Play Store is interesting, but we're sure Google will have thought of this. After all, there's a lot of devices out there running some build or other of Jelly Bean. I've been running ART on both of my devices for a long time now and I'm more than happy with it, however there are some issues when certain apps don't support ART. We're sure to hear more of this come next week during Google I/O.